Testplan

Testpoints

Stage V1 Testpoints

smoke

Test: usbdev_smoke

Smoke test of data transfers in each direction, on both the CSR interface (buffer read/write) and the USB (packet transmission/reception).

  • DV environment programs CSRs for suitable pin configuration, leaving the device unconnected by not driving the DP pullup.
  • Program CSRs to enable SETUP packet reception, OUT traffic and IN traffic to a chosen endpoint.
  • Present a buffer description in the AvSetup Buffer FIFO, to receive the SETUP packet.
  • Enable the interface (assert DP pull up) to indicate device presence.
  • DV host-side detects device presence.
  • DV host-side transmits a SETUP packet to device address 0, chosen endpoint.
  • Check that the description of the SETUP packet appears in the RxFiFo, with the expected ‘setup’ indicator, buffer ID, and a packet length of 8 bytes.
  • Check that the SETUP packet has been received into the packet buffer memory and that the buffer holds the expected content.
  • DV host-side checks that ACK was received from usbdev in response to the SETUP packet.
  • Repeat the above for a regular OUT data packet using the AvOut Buffer FIFO, using the same endpoint.
  • Populate a buffer with known randomized packet data for collection from a randomly-chosen endpoint.
  • Program CSRs to present the packet for collection by the host.
  • DV host-side transmits an IN request to device address 0, chosen endpoint.
  • DV host-side collect IN DATA packet, and ACKnowledges receipt.
  • Check that the received packet matches against that data written into the buffer.
  • Check that CSRs indicate that the packet has been sent.

csr_hw_reset

Test: usbdev_csr_hw_reset

Verify the reset values as indicated in the RAL specification.

  • Write all CSRs with a random value.
  • Apply reset to the DUT as well as the RAL model.
  • Read each CSR and compare it against the reset value. it is mandatory to replicate this test for each reset that affects all or a subset of the CSRs.
  • It is mandatory to run this test for all available interfaces the CSRs are accessible from.
  • Shuffle the list of CSRs first to remove the effect of ordering.

csr_rw

Test: usbdev_csr_rw

Verify accessibility of CSRs as indicated in the RAL specification.

  • Loop through each CSR to write it with a random value.
  • Read the CSR back and check for correctness while adhering to its access policies.
  • It is mandatory to run this test for all available interfaces the CSRs are accessible from.
  • Shuffle the list of CSRs first to remove the effect of ordering.

csr_bit_bash

Test: usbdev_csr_bit_bash

Verify no aliasing within individual bits of a CSR.

  • Walk a 1 through each CSR by flipping 1 bit at a time.
  • Read the CSR back and check for correctness while adhering to its access policies.
  • This verify that writing a specific bit within the CSR did not affect any of the other bits.
  • It is mandatory to run this test for all available interfaces the CSRs are accessible from.
  • Shuffle the list of CSRs first to remove the effect of ordering.

csr_aliasing

Test: usbdev_csr_aliasing

Verify no aliasing within the CSR address space.

  • Loop through each CSR to write it with a random value
  • Shuffle and read ALL CSRs back.
  • All CSRs except for the one that was written in this iteration should read back the previous value.
  • The CSR that was written in this iteration is checked for correctness while adhering to its access policies.
  • It is mandatory to run this test for all available interfaces the CSRs are accessible from.
  • Shuffle the list of CSRs first to remove the effect of ordering.

csr_mem_rw_with_rand_reset

Test: usbdev_csr_mem_rw_with_rand_reset

Verify random reset during CSR/memory access.

  • Run csr_rw sequence to randomly access CSRs
  • If memory exists, run mem_partial_access in parallel with csr_rw
  • Randomly issue reset and then use hw_reset sequence to check all CSRs are reset to default value
  • It is mandatory to run this test for all available interfaces the CSRs are accessible from.

regwen_csr_and_corresponding_lockable_csr

Tests:

  • usbdev_csr_rw
  • usbdev_csr_aliasing

Verify regwen CSR and its corresponding lockable CSRs.

  • Randomly access all CSRs
  • Test when regwen CSR is set, its corresponding lockable CSRs become read-only registers

Note:

  • If regwen CSR is HW read-only, this feature can be fully tested by common CSR tests - csr_rw and csr_aliasing.
  • If regwen CSR is HW updated, a separate test should be created to test it.

This is only applicable if the block contains regwen and locakable CSRs.

mem_walk

Test: usbdev_mem_walk

Verify accessibility of all memories in the design.

  • Run the standard UVM mem walk sequence on all memories in the RAL model.
  • It is mandatory to run this test from all available interfaces the memories are accessible from.

mem_partial_access

Test: usbdev_mem_partial_access

Verify partial-accessibility of all memories in the design.

  • Do partial reads and writes into the memories and verify the outcome for correctness.
  • Also test outstanding access on memories

Stage V2 Testpoints

in_trans

Test: usbdev_in_trans

Verify read and write 1 to clear corresponding bits of the ‘in_sent’ register.

  • Configure the device for an IN transaction to a particular endpoint.
  • Read the ‘in_sent’ register value to get current status of sent packets and then write 1s to the bits which are already high.
  • Verify that reading the register shows only those bits high whose corresponding endpoints have sent a packet, and - for non-Isochronous transfers - received an ACK from the host.
  • Writing ones must clear the corresponding bits of the ‘in_sent’ register.

data_toggle_clear

Test: usbdev_data_toggle_clear

Verify the ability to clear Data Toggle bits.

  • Set any random bit of the data toggle register from bit 0 to bit 11 then initiate an IN/OUT transaction on the corresponding endpoint whose bit is asserted.
  • Verify that writing 0 to a particular bit (bits 0-11) resets the data toggle bit for that particular IN/OUT endpoint to DATA0, to resynchronize with the USB host.
  • But it does not prevent toggling of the flags upon successful transmission/receipt of subsequent data packets.

phy_pins_sense

Test: usbdev_phy_pins_sense

Verify that the ‘phy_pins_sense’ register reflects the current state of the DUT pins.

  • Read the ‘phy_pins_sense’ register via TL-UL interface and sample the input and output signals of the DUT at that particular instant.
  • Verify that the read value of the register reflects the sampled values of the inputs and outputs.

av_buffer

Test: usbdev_av_buffer

Verify the behavior of the Available OUT and Available SETUP Buffer FIFOs.

  • Choose at random whether to send a SETUP packet or an OUT packet.
  • Write a random 5-bit buffer ID into the ‘avoutbuffer’ or ‘avsetupbuffer’ as appropriate.
  • Send a SETUP/OUT token packet followed by a DATA packet to the DUT.
  • Verify that the packet arrives in the RX FIFO with the expected properties (buffer ID, packet length and setup/non-setup packet).
  • Verify that the specified buffer within the packet buffer memory contains the data that was transmitted.

rx_fifo

Test: usbdev_pkt_buffer

Verify the functionality of rx fifo.

  • Send an OUT transaction to the DUT with appropriate data packet.
  • After successful reception read the buffer id, setup/out flag and size from the RX FIFO entry.
  • Then perform a read operation on the SRAM with address and control info provided by the rxfifo.
  • Verify that the data read from the SRAM matches the data sent to the device in the data packet of the OUT transaction.

phy_config_tx_osc_test_mode

Test: usbdev_phy_config_tx_osc_test_mode

Verify the oscillator test mode when phy_config.tx_osc_test_mode is enabled.

  • Set the phy_config.tx_osc_test_mode.
  • Verify that the device starts transmitting the J/K pattern continuously.

phy_config_eop_single_bit_handling

Test: usbdev_phy_config_eop_single_bit_handling

Verify the correct behavior of the phy_config.eop_single_bit configuration in the PHY module where a single SE0 bit is recognized as an end of packet, while two successive bits are required otherwise.

  • Set eop_single_bit field true in the ‘phy_config’ register and then send an OUT data packet with a single SE0 bit interval at the end followed by J state (bus Idle).
  • Verify that the device recognizes this EOP as valid, accepts the packet into the RX FIFO and does not ignore the packet or raise any link_err interrupts.

phy_config_pinflip

Test: usbdev_phy_config_pinflip

Verify that the ‘phy_config.pinflip’ bit swaps the use of the DP and DN signals on both the input and the output sides of the DUT.

  • Set up the DUT as normal but ensure that the ‘pinflip’ bit is instead set to true.
  • Ensure that the agent, including driver and monitor are aware of the pins being swapped.
  • Connect the device to the USB.
  • Verify that USB_DN is pulled high instead of USB_DP, and that USB_DP remains low.
  • Verify that OUT and and IN transactions complete normally and with the expected data being transferred.

phy_config_usb_ref_disable

Test: usbdev_phy_config_usb_ref_disable

Verify the reference signal generation for clock synchronization may be disabled.

  • Generate a number of SOF packets to the DUT.
  • Check that the ‘usb_ref_val_o’ rises indicating that valid packets are being detected.
  • Check that ‘usb_ref_pulse_o’ pulses periodically, in time with the transmission of SOF packets to the DUT.
  • Set the usb_ref_disable field true in the phy_config register, but continue to transmit the SOF packets.
  • Verify that the ‘usb_ref_val_o’ becomes deasserted and ‘usb_ref_pulse_o’ no longer pulses in response to the arrival of SOF packets.

max_length_out_transaction

Test: usbdev_max_length_out_transaction

Verify the reception of maximum length OUT data packets.

  • Configure the endpoint with ‘rxenable_out’ bit set and ‘ep_enable_out’ set.
  • Host sends an OUT token followed by the data packet with maximum payload length of 64 bytes.
  • Verify that the DUT acknowledges through an ACK handshake packet.
  • Check that the received data packet within the DUT packet buffer memory matches the packet data that was transmitted.

max_length_in_transaction

Test: usbdev_max_length_in_transaction

Verify the transmission of maximum length IN data packets.

  • Configure the DUT to present a known packet of maximum length (64 bytes) for collection by the host.
  • Host sends an IN token, then device sends the data packet with maximum payload length of 64 bytes.
  • Verify that the usbdev responds appropriately to the ACK by recording that the IN DATA packet was successfully transmitted.
  • DV host-side shall check that the IN data packet contains the expected data with no bit stuffing errors and with a correct CRC16.

min_length_out_transaction

Test: usbdev_min_length_out_transaction

Verify the reception of minimum length OUT data packets.

  • Configure the endpoint with ‘rxenable_out’ bit set and ‘ep_enable_out’ set.
  • Host sends an OUT token followed by the data packet with minimum payload length of 0 bytes.
  • Verify that the DUT acknowledges through an ACK handshake packet.
  • Check that the received data packet within the DUT packet buffer memory matches the packet data that was transmitted.

min_length_in_transaction

Test: usbdev_min_length_in_transaction

Verify the transmission of minimum length IN data packets.

  • Configure the DUT to present the known packet of minimum length (0 bytes) for collection by the host.
  • Host sends an IN token, then device sends the data packet with minimum payload length of 0 bytes.
  • Verify that the usbdev responds appropriately to the ACK by recording that the IN DATA packet was successfully transmitted.
  • DV host-side shall check that the IN data packet contains the expected data with no bit stuffing errors and with a correct CRC16.

random_length_out_transaction

Test: usbdev_random_length_out_transaction

Verify the reception of random length OUT data packets.

  • Configure the endpoint with ‘rxenable_out’ bit set and ‘ep_enable_out’ set.
  • Host sends an OUT token followed by the data packet with random payload length between 0 and 64 bytes.
  • Length from 0 inclusive to 64 inclusive should be supported.
  • Verify that the DUT acknowledges receipt with an ACK handshake packet.

random_length_in_transaction

Test: usbdev_random_length_in_transaction

Verify the transmission of random length IN data packets.

  • Configure the DUT to present a packet of known random length (0-64 bytes, inclusive) and content for collection by the host.
  • Host sends an IN token, then device sends the data packet.
  • Verify that the DUT records successful transmission of the data packet by setting the corresponding bit of the ‘in_sent’ register.

out_stall

Test: usbdev_out_stall

Verify the functionality of OUT endpoint stall.

  • Set the ‘out_stall’ register’s bit to 1 for a particular endpoint, then host issues an OUT token packet followed by data packet for that endpoint.
  • Verify that the device responds with the PID STALL Handshake.

in_stall

Test: usbdev_in_stall

Verify the functionality of IN endpoint stall.

  • Set the ‘in_stall’ register’s bit to 1 for a particular endpoint, then host issues an IN token packet for a particular endpoint.
  • Verify that the device responds with the PID STALL Handshake.

out_iso

Test: usbdev_out_iso

Verify the functionality of isochronous transfer for OUT transaction.

  • Set the ‘out_iso’ register’s bit to 1 for a paricular endpoint, then host issues an OUT token to that endpoint followed by the OUT data packet.
  • Verify that the device does not send any handshake packet in response.

in_iso

Test: usbdev_in_iso

Verify the functionality of isochronous transfer for IN transaction.

  • Set the ‘in_iso’ register’s bit to 1 for an endpoint, then host issues an IN token to that endpoint.
  • Configure the DUT with a data packet availabile for collection from that endpoint.
  • Host sends an IN request and collects the IN data packet, but does not send a handshake response.
  • Verify that the device signals successful transmission of the packet via the ‘in_sent’ register without awaiting a handshake packet from the host.

pkt_received

Test: usbdev_pkt_received

Verify the interrupt functionality of packet reception.

  • Send an OUT/SETUP token packet to an enabled endpoint while enabling the INTR_ENABLE[0] followed by the data.
  • Verify that the corresponding interrupt pin goes high after the successful OUT/SETUP packet reception.

pkt_sent

Test: usbdev_pkt_sent

Verify the interrupt functionality of packet transmission.

  • Send an IN transaction token packet to an enabled endpoint while INTR_ENABLE[1] is 1.
  • Verify that the corresponding interrupt pin goes high after sending the successful IN packet.

disconnected

Test: usbdev_disconnected

Verify that if VBUS is lost then link is disconnected.

  • VBUS(sense) is set to 0 while INTR_ENABLE[2] is 0.
  • Verify that the corresponding Interrupt pin goes high after the link disconnected.

host_lost

Test: usbdev_host_lost

Verify that if link is active (ie. not completely idle) but SOF was not received from host for 4.096 ms, the ‘host lost’ interrupt becomes asserted.

  • Note that there must be some non-idle signaling on the USB during this time because otherwise the link state will become suspended, and ‘host lost’ will not be signaled.
  • Send SOF from host after 4.096 ms while INTR_ENABLE [3] is set.
  • Verify that the corresponding interrupt pin goes high once the host is lost.
  • SOF should normally be received every 1 ms.

Test: usbdev_link_reset

Verify that if the link is at SE0 longer than 10 us indicating a link reset (host asserts for min 10 ms, device can react after 2.5 us) then link reset will raise.

  • Send an SE0 Signal for close to the 10 ms. while INTR_ENABLE [4] is set.
  • Verify that the interrupt pin link_reset goes high once the link reset.

Test: usbdev_link_suspend

Verify that if the line has signaled J (Idle) for longer than 3 ms and is therefore in suspend state the ‘link suspend’ will be raised.

  • Leave the link in idle state for more than 3 ms while enable the INTR_ENABLE [5] is set and also set the wake_control.suspend_req afterwards.
  • Verify that the interrupt pin goes high once the link suspended.

Test: usbdev_link_resume

Verify that when the link becomes active again after being suspended link resume will rise.

  • First suspend the link by keeping J signal for 3.1ms and then resume it by changing the polarity for 20ms. While the INTR_ENABLE[6] bit is set, also set the wake_control.wake_ack signal.
  • Verify that the interrupt pin link_resume goes high once the link resume.

av_empty

Test: usbdev_av_empty

Verify the functionality of ‘av_out_empty’ and ‘av_setup_empty’ interrupts when the Av OUT/SETUP Buffer FIFO is empty.

  • Choose at random whether to test the AV OUT Buffer FIFO or the AV SETUP Buffer FIFO.
  • Enable the interrupt for AV OUT/SETUP empty by setting INTR_ENABLE[7/17] and then send back to back packets to the device.
  • Receive and discard any buffers that appear in the RX FIFO.
  • Verify that this interrupt pin goes high once the Av OUT/SETUP Buffer FIFO is empty.

rx_full

Test: usbdev_rx_full

Verify the functionality of rx_full signal when RX FIFO is full.

  • Enable the interrupt for RX full by setting INTR_ENABLE[8] and then send back to back packets to the device.
  • Don’t service the packets received by popping out from rx_fifo; leave it to become full.
  • Verify that this interrupt pin goes high once the received fifo is full.

av_overflow

Test: usbdev_av_overflow

Verify that if a write was done to either the Available OUT Buffer FIFO or the Available SETUP Buffer FIFO when the FIFO was full the ‘av_overflow’ signal becomes high.

  • Fill both of the Available buffer FIFOs.
  • Choose at random whether to supply an additional OUT buffer or a SETUP buffer.
  • Attempt to write a buffer ID to the chosen FIFO.
  • Verify that this interrupt pin goes high indicating that the available fifo has reached the overflowing condition.

Test: usbdev_link_in_err

Verify that if a packet to an IN endpoint started to be received but was then dropped due to an error then link_in_err will raise.

  • Send an IN token to the device for initiating an IN transaction.
  • The device should respond with an IN data packet.
  • DV environment returns an invalid crc16 or unexpected PID in the handshake packet.
  • Verify that the link_in_err interrupt goes high following the handshake packet sent by the host.

rx_crc_err

Test: usbdev_rx_crc_err

Verify that if a CRC error occurred then rx_crc_err will raise.

  • Send a token/data packet to the device while intentionally corrupting any of the CRC bits.
  • Verify that the rx_crc_err goes high following the reception of the invalid packet.

rx_pid_err

No Tests Implemented

Verify that if an invalid packed identifier (PID) was received then rx_pid_err will raise.

  • send an invalid PID to the device with the higher bits not complementing the lower bits.
  • Verify that the interrupt pin goes high indicating PID error.

rx_bitstuff_err

Test: usbdev_bitstuff_err

Verify that if an invalid bit stuffing was received then rx_bitstuffing_err will raise.

  • generate a packet with 7 consecutive ones (bypassing bitstufffing) on data line.
  • Verify that the interrupt pin goes high indicating bitstuff error.

Test: usbdev_link_out_err

Verify that if a packet to an OUT endpoint started to be received but was then dropped due to an error then link_out_err will raise.

  • send an out packet to the device with invalid crc, token, avbuffer_empty, rx_fifo full conditions.
  • Verify that the interrupt pin goes high indicating an error in the link in OUT transaction.

enable

Test: usbdev_enable

Verify that DUT connects to the USB when enable is set.

  • set USB_CTRL_enable pin high.
  • Make sure ‘phy_config.pinflip’ isn’t set.
  • Verify that the ‘usb_dp_pullup_o’ pin goes high.

Test: usbdev_resume_link_active

Verify that the DUT moves from the LinkPowered state to the LinkResuming state in response to the ‘resume_link_active’ bit being set.

  • Disconnect VBUS.
  • Read the link state from usbstat register to see if it is in Disconnected state and restore VBUS and the pull up.
  • The DUT should move to the Powered state.
  • Send resume signaling (K state) for 20 ms and set the usbctrl.resume_link_active.
  • Verify that the DUT moves into the Resuming state and subsequently ActiveNoSOF.

device_address

Test: usbdev_device_address

Verify that the device ignores all packets with addresses that do not match the assigned device address.

  • Assign device address to (usbctrl[22:16]) and send packets to this address.
  • Send packets to other addresses.
  • Verify that the device responds to all packets sent by the DV environment (USB side) to the assigned address.
  • Verify that the device ignores all packets that are sent to other addresses.

invalid_data1_data0_toggle_test

Test: usbdev_invalid_data1_data0_toggle_test

Verify the detection and reporting of unexpected Data Toggle bits.

  • Send a sequence of OUT data packets to the device without toggling between DATA0 and DATA1 PIDs in consecutive data packets.
  • Verify that the interrupt pin goes high indicating a link error during OUT transactions.

setup_stage

Test: usbdev_setup_stage

Verify the SETUP stage of enumeration.

  • Send a setup token with a valid setup packet followed by a DATA0 packet requesting information about device i.e. descriptors.
  • Verify that the device ACKs the setup packet.

endpoint_access

Test: usbdev_endpoint_access

Verify the accessibility of all endpoints when endpoints are enabled.

  • Access all the endpoints of the device in IN and OUT direction by enabling ep_out_enable and ep_in_enable along with rxenable_out for OUT transaction.
  • Verify that the device allows access to all endpoints by responding with ACK for OUT accesses and data_packet for IN Accesses.

disable_endpoint

Test: usbdev_disable_endpoint

Verify that packet transmission (IN and SETUP) and reception requests (IN) are ignored when endpoints are disabled.

  • Disable an endpoint by clearing bit of ep_out_enable and ep_in_enable.
  • Then initiate an IN/OUT transaction to that endpoint.
  • Verify that the Out transactions as well as IN transactions sent to the device on the particular endpoint will be ignored.

out_trans_nak

Test: usbdev_out_trans_nak

Verify the functionality of OUT transaction when rxenable_out is not set.

  • clear a particular endpoint bit for rx_enable_out register.
  • Then send an out transaction to that endpoint.
  • Verify that the OUT transactions shall be NAKED by OUT endpoints.

setup_trans_ignored

Test: usbdev_setup_trans_ignored

Verify the functionality of SETUP transaction when rxenable_setup is not set.

  • clear a particular endpoint bit for rxenable_setup register.
  • Then send a setup transaction to that endpoint.
  • Verify that the SETUP transactions shall not be received by enabled OUT endpoints if rxenable_setup is not set.

nak_trans

Test: usbdev_nak_trans

Verify the functionality of OUT transaction when set_nak_out is set.

  • Set_nak_out and rxenable_out are both set
  • Issue OUT transaction and observe it complete.
  • Observe rxenable_out cleared.
  • Issue OUT transaction and observe it get NAK’d.
  • Verify that the OUT transactions shall be NAKED for disabled endpoint and the corresponding bit in rxenable_out register will be cleared.

stall_trans

Test: usbdev_stall_trans

Verify that enabling out_stall shall cause STALL response to attempted OUT transactions.

  • Set out_stall register bits for a particular transaction.
  • Verify that we will get STALL response when we try to attempt OUT transactions.

setup_priority_over_stall_response

No Tests Implemented

Verify that by enabling STALL response shall not prevent the reception of a SETUP transaction/packet.SETUP shall clear both in_stall and out_stall bits for the endpoint.

  • Configure an endpoint for stall response to out transactions then send a setup transaction to the device on stalled endpoint.
  • Verify that the SETUP being higher in priority shall clear both in_stall and out_stall bits for that endpoint

stall_priority_over_nak

Test: usbdev_stall_priority_over_nak

Verify that if the configuration has both STALL and NAK enabled the STALL handshake will take priority.

  • Configure an endpoint with STALL as well as NAK responses then issue an OUT transaction to that endpoint.
  • Verify that the STALL being higher in priority will take precedence over NAK responses.

pending_in_trans

Test: usbdev_pending_in_trans

Verify that the a Link Reset or SETUP transaction cancels any waiting IN transactions by clearing the rdy bit in the configin register of all endpoints.

  • Configure an endpoint for transmission by setting fields in ‘configin[ep]’ register and then setting the ‘rdy’ bit to 1.
  • Send a SETUP transaction to that endpoint or issue a link reset.
  • Verify that the ‘rdy’ bit in ‘configin[ep]’ is cleared and the ‘pend’ bit is set to 1.

streaming_test

Test: usbdev_streaming_out

Verify the streaming capability of an endpoint in OUT transaction mode.

  • Issue back to back data packets to a particular enabled endpoint.
  • Read the information from RX FIFO as soon as a packet is received along with the buffer in the SRAM.
  • Send the buffer ID back to Available buffer FIFO after successful buffer read.
  • Verify that the device is capable of handling the streaming traffic for a large number of iterations without Available OUT Buffer FIFO becoming empty or the RX FIFO becoming full.

max_clock_error_untracked

No Tests Implemented

Verify the functionality of DUT at maximum clock frequency deltas. This test does not attempt to model the adjustment of the usb_clk oscillator, in response to SOF packets received from the USB host, and therefore cannot support the full frequency mismatch required by the USB 2.0 protocol specification.

  • Clock the device and the agent with opposite extremes of allowable frequency ranges and initiate a transaction with maximum data length.
  • Verify that the transactions occur successfully between the device and host agent in both directions, and that all transmitted bytes are decoded correctly.
  • Verify that there are no reports of bit stuffing errors or CRC errors.

max_clock_error_tracking

No Tests Implemented

Verify the functionality of DUT at maximum clock frequency difference, adjusting the frequency of ‘usb_clk’ in response to the arrival times of the SOF packets sent from the USB host agent.

  • Implement tracking of the SOF packets from the host, using the ‘usb_ref_pulse_o’ signal from the DUT to adjust the USB device clock.
  • With the USB host agent operating at the maximum frequency permissible within the USB 2.0 protocol specification, start the USB device operating at the minimum permissible frequency and check that SOF packets are still received and decoded correctly.
  • Check that the ‘usb_ref_pulse_o’ signal is produced as expected, and that the ‘usb_clk’ signal increases in frequency to match that of the USB host agent.
  • Verify that full length packet transmission to and from the host occurs successfully without reports of bit stuffing errors or CRC errors.
  • Repeat the above with the USB host agent at the minimum permissible frequency and the USB device starting at the maximum frequecy.

max_phase_error

No Tests Implemented

Verify that the device and host can work in different phase corners of the 48 MHz clock.

  • Clock the device and the agent with opposite corners of phases and initiate a transaction with maximum data length.
  • Verify that the transaction between the host agent and device must be successful by raising interrupts for succesful packet reception or transmission after the end of the transaction.

min_inter_pkt_delay

Test: usbdev_min_inter_pkt_delay

Verify the minimum 2 bit times from the SE0-to-J transition (from EOP) to the J-to-K transition.

  • Send at random either a SETUP token packet or an OUT token packet to the DUT.
  • After just 2 bit intervals of Idle state, transmit a DATA packet to the DUT.
  • Verify that the packet is received, decoded correctly and ACKnowledged by the DUT.

max_inter_pkt_delay

Test: usbdev_max_inter_pkt_delay

Verify the maximum 7.5 bit times from the SE0-to-J transition (from EOP) to the J-to-K transition.

  • Send at random either a SETUP token packet or an OUT token packet to the DUT.
  • After 7.5 bit intervals of Idle state, transmit a DATA packet to the DUT.
  • Verify that the packet is received, decoded correctly and ACKnowledged by the DUT.

device_timeout_missing_host_handshake

No Tests Implemented

Verify that the device times out an IN transaction if it does not receive a handshake response from the host.

  • Configure the DUT to present a single packet for IN collection.
  • Collect a non-Isochronous IN packet from the DUT but do not send a handshake packet.
  • Host sends a random choice of SETUP, OUT or IN token packet to the DUT.
  • Check that the packet is still marked as ‘rdy’ and that ‘in_sent’ is not set.
  • Retry the IN packet collection and this time send the ACK handshake within the normal response period.
  • Check that that packet is collected, that ‘rdy’ is cleared and that the ‘in_sent’ register bit indicates successful transmission of the packet.

device_timeout

No Tests Implemented

Verify that the device times out transactions when a host response is 18 bit times after the packet transmitted by the DUT.

  • Configure the DUT to present a single packet for IN collection.
  • Collect a non-Isochronous IN packet from the DUT but do not send a handshake packet in response within 18 bit intervals.
  • Check that the packet is still marked as ‘rdy’ and that ‘in_sent’ is not set.
  • Send a delayed ACKnowledge handshake packet to the DUT.
  • Check that the packet is still marked as ‘rdy’ and that ‘in_sent’ is not set.
  • Retry the IN packet collection and this time send the ACK handshake within the normal response period.
  • Check that that packet is collected, that ‘rdy’ is cleared and that the ‘in_sent’ register bit indicates successful transmission of the packet.

packet_buffer

Test: usbdev_pkt_buffer

Exercise all buffers within the packet buffer memory, performing reads and writes of packet buffer data from both sides (CSR and USB) simultaneously.

  • Randomly choose between IN and OUT packet transfer on the USB side.
  • Randomly choose between buffer read and buffer write on the CSR side.
  • Ensure, however, that the CSR side and the USB side never access the same buffer simultaneously; this is guaranteed by the contract that exists between hardware and software.
  • Check all transferred data on both sides.
  • Ensure that it is possible for individual read and write accesses to occur at the packet buffer memory from both sides within the same cycle. Since the packet buffer memory is now a Single Port RAM implementation, this requires the CSR-side access to be delayed until the USB side is idle.

nak_to_out_trans_when_avbuffer_empty_rxfifo_full

Test: usbdev_nak_to_out_trans_when_avbuffer_empty_rxfifo_full

Verify that the device sends out NAK responses to OUT transactions when available buffer is empty and RX FIFO is full.

  • send out packets to the device at such a rate that avbuffer gets empty and RX Fifo becomes full.
  • Verify that the device unable to consume packets at such a rate will set NAK responses even though endpoint is enabled.

aon_wake_resume

Test: usbdev_aon_wake_resume

Verify that the AON/Wake module is able to detect Resume Signaling and indicate that via the USB device register interface.

  • Connect the USB device to the USB host model.
  • Send Suspend Signaling to the USB device.
  • Verify that the ‘link_suspend’ interrupt is raised indicating that the USB has been Idle (J) for at least 3ms.
  • Enable the AON/Wake module, leaving it to maintain the pull up state.
  • Initiate Resume Signaling, driving the USB into the ‘K’ state.
  • Check that the ‘wake_req_aon_o’ signal from the ‘usbdev_aon_wake’ module becomes asserted.
  • Read from the ‘wake_events’ CSR of the USB device and check that the ‘bus_not_idle’ bit is asserted.
  • Disable the AON/Wake module and verify that the USB device is still connected, ie. the DP pullup is enabled and DP is high.

aon_wake_reset

Test: usbdev_aon_wake_reset

Verify that the AON/Wake module is able to detect Reset Signaling and indicate that via the USB device register interface.

  • Connect the USB device to the USB host model.
  • Enable the AON/Wake module, leaving it to maintain the pull up state.
  • Perform a Bus Reset, driving SE0 state onto the USB for at least 10us; the specification requires at least 10ms of Reset Signaling for a full reset, but the AON/Wake module should respond a lot faster, to allow time for chip start up and software reinitialization.
  • Check that the ‘wake_req_aon_o’ signal from the ‘usbdev_aon_wake’ module becomes asserted.
  • Read from the ‘wake_events’ CSR of the USB device and check that the ‘bus_reset’ bit is asserted.
  • Disable the AON/Wake module and verify that the USB device is still connected, ie. the DP pullup is enabled and DP is high.

aon_wake_disconnect

Test: usbdev_aon_wake_disconnect

Verify that the AON/Wake module is able to detect Bus Disconnection and indicate that via the USB device register interface.

  • Connect the USB device to the USB host model.
  • Enable the AON/Wake module, leaving it to maintain the pull up state.
  • Verify that the DP pull up remains asserted, indicating the presence of the device on the USB.
  • Lower the VBUS/SENSE signal.
  • Check that the ‘wake_req_aon_o’ signal from the ‘usbdev_aon_wake’ module becomes asserted.
  • Read from the ‘wake_events’ CSR of the USB device and check that the ‘disconnected’ bit is asserted.
  • Check that the DP pull up is no longer asserted; it shall be dropped by the usbdev_aon_wake module to protect against spurious reconnection.
  • Disable the AON/Wake module and verify that the USB device remains disconnected.

invalid_sync

Test: usbdev_invalid_sync

Randomized interspersing of valid and invalid USB traffic. Generate bit-level changes on the USB that do not constitute valid SYNC signaling, interspersed with valid USB traffic to/from the device.

  • Set up the device with a single IN and a single OUT endpoint.
  • Fully populate the Available OUT Buffer FIFO.
  • Stream and check known traffic to (OUT) and from (IN) the device, with the CSR side simply returning unmodified every OUT packet that is received.
  • Randomly select whether to send an OUT packet, request an IN packet or generate invalid noise (never including a valid SYNC signal) on the USB.
  • Verify that all data has been streamed successfully, and that the USB device continued to operate correctly, ignoring all of the invalid signaling.

spurious_pids_ignored

Test: usbdev_spurious_pids_ignored

Check that the device ignores packets with unexpected tokens such as NYET, PRE… Also test ACK and NAK when not in response to a transmitted IN packet.

  • Randomly transmit valid token packets that use unexpected/unsupported PIDs and, in the case of ACK/NAK handshake packet that are out of sequence.
  • This is important in ensuring that the USB device/communications does not fail in the event of host handshake responses (to IN packets) being delayed.
  • Test all possible PIDs other than SETUP, OUT and IN, including invalid PIDs where the lower and upper nibbles are not complementary, and DATA0 and DATA1 PIDs without a preceding SETUP, OUT or IN token packet.

low_speed_traffic

No Tests Implemented

Test that Low Speed traffic on the bus in the downstream direction is appropriately ignored and does not cause the USB device to enter an invalid state. Background: Hubs are permitted to propagate downstream Low Speed signaling to Full Speed devices on other ports.

  • Connect the USB device, with a SETUP- and OUT-capable endpoint.
  • Repeatedly generate and check valid SETUP and OUT packets at Full Speed signaling speeds, whilst interspersing Full Speed traffic that consists of PRE tokens followed by randomized packet contents at Low Speed signaling.
  • Check that the USB device receives correctly all of the SETUP and OUT packets and is unaffected by the Low Speed signaling.
  • In particular, check that it does not generate unexpected interrupts because these could devalue the diagnostic use of those interrupts in detecting and reporting unreliable connections.

rand_bus_resets

Test: usbdev_rand_bus_resets

Ensure that all of SETUP, OUT and IN traffic are robust against randomized bus resets from the USB and that communications may successfully be resumed after subsequent reconfiguration.

  • Configure the USB device to receive SETUP, OUT and IN traffic (the regular Default Pipe, ie. just Endpoint Zero, should suffice).
  • During the process of normal device configuration, issue a Bus Reset to the device at a random time (ensuring that it may occur during all transaction types), and then restart the configuration, checking that it completes successfully this time when no reset occurs.
  • The intention is to ensure that the internal state machines and logic do not get stuck or hold persistent inappropriate state.

rand_disconnects

Test: usbdev_rand_bus_disconnects

Ensure that all of SETUP, OUT and IN traffic are robust against randomized disconnection of the USB and that communications may successfully be resumed after a bus reset and reconfiguration. (The bus reset should occur have a disconnection that was host-initiated, and before configuration traffic commences.)

  • Configure the USB device to receive SETUP, OUT and IN traffic (the regular Default Pipe, ie. just Endpoint Zero should suffice).
  • During the process of normal device configuration, disconnect the USB at a random time (ensuring that it may occur during all transaction types), and then restart the configuration after a Bus Reset and check that configuration completes successfully this time when no disconnection occurs.

max_usb_traffic

Test: usbdev_max_usb_traffic

Verify operation under maximal traffic to maximal endpoints, exercising all transfer types and all packet lengths, with randomized delays on the CSR side when receiving packets, supplying packets, making buffers available for use, and responding to interrupts.

stress_usb_traffic

Test: usbdev_stress_usb_traffic

Derived from ‘max_usb_traffic’ this also randomly introduces unexpected token packets, low speed traffic, invalid traffic, bus resets and disconnects, to ensure that these do not interfere with the transmission and reception of valid traffic.

in_packet_retraction

No Tests Implemented

Exercise retraction of IN packets for Isochronous streams, prioritizing the delivery of the most recent data over the reliable delivery of all data presented.

  • Configure a single IN endpoint for Isochronous support.
  • Repeatedly poll for and collect IN packets from the USB host model, randomizing the delays between collection attempts.
  • Present a stream of Isochronous packets on the IN endpoint, with each packet containing a serial number. Randomize the times between packet presentations, and keep on the CSR side a record of which packets were retracted/overwritten rather than being transmitted successfully to the host.
  • Check that the CSR side and the USB host model agree on which packets were successfully transmitted from the device to the host.

data_toggle_restore

Test: usbdev_data_toggle_restore

Verify that each of the IN and OUT Data Toggle bits may be both set and cleared by software to ensure that resuming communications after returning from Deep Sleep is possible.

  • Ensure that the USB device disconnected (pull up not enabled) such that no communications shall occur with the device.
  • Set all of the even-numbered OUT Data Toggle bits to 1 and all of the odd-numbered OUT Data Toggle bits to 0.
  • Check that the OUT Data Toggle bits read as 0x555.
  • Set all of the even-numbered IN Data Toggle bits to 0 and all of the odd-numbered IN Data Toggle bits to 1.
  • Check that the IN Data Toggle bits read as 0xAAA.
  • Check that the OUT Data Toggle bits read as 0x555.
  • Invert all of the OUT Data Toggle bits.
  • Invert all of the IN Data Toggle bits.
  • Check that the OUT Data Toggle bits read as 0xAAA.
  • Check that the IN Data Toggle bits read as 0x555.
  • Set all of the OUT Data Toggle bits to random values.
  • Set all of the IN Data Toggle bits to random values.
  • Check that all of the OUT and IN Data Toggle bits read back as expected.
  • Test the interaction of USB traffic with the IN and OUT Data Toggle bits, but note that data toggle bits may only be toggled safely between packets.

setup_priority

Test: usbdev_setup_priority

Verify that the final slot of the Rx FIFO is reserved for use by SETUP packets only. The final slot of the Rx FIFO buffer shall never be assigned to an OUT DATA packet because it could force the USB device to be unresponsive to a SETUP DATA packet.

  • Configure the USB device to receive SETUP packets on Endpoint Zero.
  • Configure endpoint 1 to receive OUT DATA packets.
  • Place 1 buffer in the Available SETUP Buffer FIFO.
  • Place 8 buffers in the Available OUT Buffer FIFO.
  • Transmit 7 OUT DATA packets to endpoint 1, checking that each packet is ACKed, but do not read from Rx FIFO.
  • Check that the Rx FIFO contains 7 buffers.
  • Transmit 1 OUT DATA packet to endpoint 1.
  • Verify that the OUT DATA packet is NAKed as expected.
  • Check that the Rx FIFO depth is still 7.
  • Transmit a SETUP DATA packet to Endpoint Zero, checking that the packet is ACKed.
  • Check that the Rx FIFO depth is now 8.
  • Read the packets from the Rx FIFO, checking the properties of each of the 7 OUT DATA packets and the final 1 SETUP DATA packet in turn.

fifo_resets

Test: usbdev_fifo_rst

Test the software-controlled FIFO reset functionality, introduced as a contingency for error recovery and to permit reconfiguration of the USB device hardware without resorting to use of the block-level asynchronous reset.

  • Populate the USBDEV FIFOs with packets randomly.
  • Choose a random set of FIFOs to reset.
  • Check the FIFO levels match expectations.
  • Note: the handling of the Received Buffer FIFO requires configuration of, and transmission of packets to, the USB device since there is no direct means to inject packets from the CSR side.

intr_test

Test: usbdev_intr_test

Verify common intr_test CSRs that allows SW to mock-inject interrupts.

  • Enable a random set of interrupts by writing random value(s) to intr_enable CSR(s).
  • Randomly “turn on” interrupts by writing random value(s) to intr_test CSR(s).
  • Read all intr_state CSR(s) back to verify that it reflects the same value as what was written to the corresponding intr_test CSR.
  • Check the cfg.intr_vif pins to verify that only the interrupts that were enabled and turned on are set.
  • Clear a random set of interrupts by writing a randomly value to intr_state CSR(s).
  • Repeat the above steps a bunch of times.

alert_test

Test: usbdev_alert_test

Verify common alert_test CSR that allows SW to mock-inject alert requests.

  • Enable a random set of alert requests by writing random value to alert_test CSR.
  • Check each alert_tx.alert_p pin to verify that only the requested alerts are triggered.
  • During alert_handshakes, write alert_test CSR again to verify that: If alert_test writes to current ongoing alert handshake, the alert_test request will be ignored. If alert_test writes to current idle alert handshake, a new alert_handshake should be triggered.
  • Wait for the alert handshakes to finish and verify alert_tx.alert_p pins all sets back to 0.
  • Repeat the above steps a bunch of times.

tl_d_oob_addr_access

Test: usbdev_tl_errors

Access out of bounds address and verify correctness of response / behavior

tl_d_illegal_access

Test: usbdev_tl_errors

Drive unsupported requests via TL interface and verify correctness of response / behavior. Below error cases are tested bases on the TLUL spec

  • TL-UL protocol error cases
    • invalid opcode
    • some mask bits not set when opcode is PutFullData
    • mask does not match the transfer size, e.g. a_address = 0x00, a_size = 0, a_mask = 'b0010
    • mask and address misaligned, e.g. a_address = 0x01, a_mask = 'b0001
    • address and size aren’t aligned, e.g. a_address = 0x01, a_size != 0
    • size is greater than 2
  • OpenTitan defined error cases
    • access unmapped address, expect d_error = 1
    • write a CSR with unaligned address, e.g. a_address[1:0] != 0
    • write a CSR less than its width, e.g. when CSR is 2 bytes wide, only write 1 byte
    • write a memory with a_mask != '1 when it doesn’t support partial accesses
    • read a WO (write-only) memory
    • write a RO (read-only) memory
    • write with instr_type = True

tl_d_outstanding_access

Tests:

  • usbdev_csr_hw_reset
  • usbdev_csr_rw
  • usbdev_csr_aliasing
  • usbdev_same_csr_outstanding

Drive back-to-back requests without waiting for response to ensure there is one transaction outstanding within the TL device. Also, verify one outstanding when back- to-back accesses are made to the same address.

tl_d_partial_access

Tests:

  • usbdev_csr_hw_reset
  • usbdev_csr_rw
  • usbdev_csr_aliasing
  • usbdev_same_csr_outstanding

Access CSR with one or more bytes of data. For read, expect to return all word value of the CSR. For write, enabling bytes should cover all CSR valid fields.

Stage V2S Testpoints

tl_intg_err

Tests:

  • usbdev_tl_intg_err
  • usbdev_sec_cm

Verify that the data integrity check violation generates an alert.

  • Randomly inject errors on the control, data, or the ECC bits during CSR accesses. Verify that triggers the correct fatal alert.
  • Inject a fault at the onehot check in u_reg.u_prim_reg_we_check and verify the corresponding fatal alert occurs

sec_cm_bus_integrity

Test: usbdev_tl_intg_err

Verify the countermeasure(s) BUS.INTEGRITY.

Covergroups

address_cg

Check that all Device Address bits are decoded and usable and that those problematic combinations with endpoint values that demand bit stuffing within the token packet have been observed.

crc16_cg

CRC16 values on packets in each direction, because CRC16 is subject to bit stuffing.

crc5_cg

Check some potentially problematic cases for bit stuffing with CRC5 in Token packets.

data_pkt_cg

Length of DATA packets in each direction

data_tog_endp_cg

Both DATA0 and DATA1 for each endpoint, and in each direction (Data Toggles), as well as both ACK and NAK (rollback and retry transaction in Packet Engines).

ep_in_cfg_cg

Receipt of IN and PRE packets with different IN endpoint configurations

ep_out_cfg_cg

Receipt of SETUP, OUT and PRE packets with different OUT endpoint configurations

fifo_lvl_cg

Received SETUP/OUT packets with FIFO levels of interest

framenum_rx_cg

Observe all significant/extreme frame numbers being reported via CSRs; this just ensures that all bits have been decoded and presented; the frame number has no significance to USBDEV but it’s important to software.

pid_type_endp_cg

All of SETUP, IN, and OUT for each endpoint

pids_cg

Observe all PIDs about which we care; a number of the available PIDs are ignored by the USB device because they related only to High Speed operation and/or hubs.

regwen_val_when_new_value_written_cg

Cover each lockable reg field with these 2 cases:

  • When regwen = 1, a different value is written to the lockable CSR field, and a read occurs after that.
  • When regwen = 0, a different value is written to the lockable CSR field, and a read occurs after that.

This is only applicable if the block contains regwen and locakable CSRs.

tl_errors_cg

Cover the following error cases on TL-UL bus:

  • TL-UL protocol error cases.
  • OpenTitan defined error cases, refer to testpoint tl_d_illegal_access.

tl_intg_err_cg

Cover all kinds of integrity errors (command, data or both) and cover number of error bits on each integrity check.

Cover the kinds of integrity errors with byte enabled write on memory if applicable: Some memories store the integrity values. When there is a subword write, design re-calculate the integrity with full word data and update integrity in the memory. This coverage ensures that memory byte write has been issued and the related design logic has been verfied.