Hardware Interfaces

Referring to the Comportable guideline for peripheral device functionality, the module usbdev has the following hardware interfaces defined

  • Primary Clock: clk_i
  • Other Clocks: clk_aon_i
  • Bus Device Interfaces (TL-UL): tl
  • Bus Host Interfaces (TL-UL): none

Peripheral Pins for Chip IO

Pin nameDirectionDescription
senseinputUSB host VBUS sense
usb_dpinoutUSB data D+
usb_dninoutUSB data D-

Inter-Module Signals

Port NamePackage::StructTypeActWidthDescription
usb_rx_dlogicunircv1USB RX data from an external differential receiver, if available
usb_tx_dlogicunireq1USB transmit data value (not used if usb_tx_se0 is set)
usb_tx_se0logicunireq1Force transmission of a USB single-ended zero (i.e. both D+ and D- are low) regardless of usb_tx_d
usb_tx_use_d_se0logicunireq1Use the usb_tx_d and usb_tx_se0 TX interface, instead of usb_dp_o and usb_dn_o
usb_dp_pulluplogicunireq1USB D+ pullup control
usb_dn_pulluplogicunireq1USB D- pullup control
usb_rx_enablelogicunireq1USB differential receiver enable
usb_ref_vallogicunireq1
usb_ref_pulselogicunireq1
usb_aon_suspend_reqlogicunireq1
usb_aon_wake_acklogicunireq1
usb_aon_bus_resetlogicunircv1
usb_aon_sense_lostlogicunircv1
usb_aon_wake_detect_activelogicunircv1
ram_cfgprim_ram_1p_pkg::ram_1p_cfgunircv1
tltlul_pkg::tlreq_rsprsp1

Interrupts

Interrupt NameTypeDescription
pkt_receivedEventRaised if a packet was received using an OUT or SETUP transaction. This interrupt is directly tied to whether the RX FIFO is empty, so it should be cleared only after handling the FIFO entry.
pkt_sentEventRaised if a packet was sent as part of an IN transaction. This interrupt is directly tied to whether a sent packet has not been acknowledged in the in_sent register. It should be cleared only after clearing all bits in the in_sent register.
disconnectedEventRaised if VBUS is lost thus the link is disconnected.
host_lostEventRaised if link is active but SOF was not received from host for 4.096 ms. The SOF should be every 1 ms.
link_resetEventRaised if the link is at SE0 longer than 3 us indicating a link reset (host asserts for min 10 ms, device can react after 2.5 us).
link_suspendEventRaised if the line has signaled J for longer than 3ms and is therefore in suspend state.
link_resumeEventRaised when the link becomes active again after being suspended.
av_out_emptyEventRaised when the Available OUT FIFO is empty and the device interface is enabled. This interrupt is directly tied to the FIFO status, so the AV FIFO must be provided a free buffer before the interrupt is cleared. If the condition is not cleared, the interrupt can re-assert.
rx_fullEventRaised when the RX FIFO is full and the device interface is enabled. This interrupt is directly tied to the FIFO status, so the RX FIFO must have an entry removed before the interrupt is cleared. If the condition is not cleared, the interrupt can re-assert.
av_overflowEventRaised if a write was done to either the Available OUT Buffer FIFO or the Available SETUP Buffer FIFO when the FIFO was full.
link_in_errEventRaised if a packet to an IN endpoint started to be received but was then dropped due to an error. After transmitting the IN payload, the USB device expects a valid ACK handshake packet. This error is raised if either the packet or CRC is invalid or a different token was received.
rx_crc_errEventRaised if a CRC error occured.
rx_pid_errEventRaised if an invalid packed identifier (PID) was received.
rx_bitstuff_errEventRaised if an invalid bitstuffing was received.
frameEventRaised when the USB frame number is updated with a valid SOF.
poweredEventRaised if VBUS is applied.
link_out_errEventRaised if a packet to an OUT endpoint started to be received but was then dropped due to an error. This error is raised if the data toggle, token, packet and/or CRC are invalid, if the Available Buffer FIFO is empty or if the Received Buffer FIFO is full.
av_setup_emptyEventRaised when the Available SETUP Buffer FIFO is empty and the device interface is enabled. This interrupt is directly tied to the FIFO status, so the AV FIFO must be provided a free buffer before the interrupt is cleared. If the condition is not cleared, the interrupt can re-assert.

Security Alerts

Alert NameDescription
fatal_faultThis fatal alert is triggered when a fatal TL-UL bus integrity fault is detected.

Security Countermeasures

Countermeasure IDDescription
USBDEV.BUS.INTEGRITYEnd-to-end bus integrity scheme.