Registers

A number of memory-mapped registers are available to control Ibex-related functionality that’s specific to OpenTitan.

Summary

Name	Offset	Length	Description
rv_core_ibex.`ALERT_TEST`	0x0	4	Alert Test Register
rv_core_ibex.`SW_RECOV_ERR`	0x4	4	Software recoverable error
rv_core_ibex.`SW_FATAL_ERR`	0x8	4	Software fatal error
rv_core_ibex.`IBUS_REGWEN_0`	0xc	4	Ibus address control regwen.
rv_core_ibex.`IBUS_REGWEN_1`	0x10	4	Ibus address control regwen.
rv_core_ibex.`IBUS_ADDR_EN_0`	0x14	4	Enable Ibus address matching
rv_core_ibex.`IBUS_ADDR_EN_1`	0x18	4	Enable Ibus address matching
rv_core_ibex.`IBUS_ADDR_MATCHING_0`	0x1c	4	Matching region programming for ibus.
rv_core_ibex.`IBUS_ADDR_MATCHING_1`	0x20	4	Matching region programming for ibus.
rv_core_ibex.`IBUS_REMAP_ADDR_0`	0x24	4	The remap address after a match has been made.
rv_core_ibex.`IBUS_REMAP_ADDR_1`	0x28	4	The remap address after a match has been made.
rv_core_ibex.`DBUS_REGWEN_0`	0x2c	4	Dbus address control regwen.
rv_core_ibex.`DBUS_REGWEN_1`	0x30	4	Dbus address control regwen.
rv_core_ibex.`DBUS_ADDR_EN_0`	0x34	4	Enable dbus address matching
rv_core_ibex.`DBUS_ADDR_EN_1`	0x38	4	Enable dbus address matching
rv_core_ibex.`DBUS_ADDR_MATCHING_0`	0x3c	4	See !!IBUS_ADDR_MATCHING_0 for detailed description.
rv_core_ibex.`DBUS_ADDR_MATCHING_1`	0x40	4	See !!IBUS_ADDR_MATCHING_0 for detailed description.
rv_core_ibex.`DBUS_REMAP_ADDR_0`	0x44	4	See !!IBUS_REMAP_ADDR_0 for a detailed description.
rv_core_ibex.`DBUS_REMAP_ADDR_1`	0x48	4	See !!IBUS_REMAP_ADDR_0 for a detailed description.
rv_core_ibex.`NMI_ENABLE`	0x4c	4	Enable mask for NMI.
rv_core_ibex.`NMI_STATE`	0x50	4	Current NMI state
rv_core_ibex.`ERR_STATUS`	0x54	4	error status
rv_core_ibex.`RND_DATA`	0x58	4	Random data from EDN
rv_core_ibex.`RND_STATUS`	0x5c	4	Status of random data in !!RND_DATA
rv_core_ibex.`FPGA_INFO`	0x60	4	FPGA build timestamp info.
rv_core_ibex.`DV_SIM_WINDOW`	0x80	32	Exposed tlul window for DV only purposes.

ALERT_TEST

Alert Test Register

Offset: 0x0
Reset default: 0x0
Reset mask: 0xf

Fields

{"reg": [{"name": "fatal_sw_err", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "recov_sw_err", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "fatal_hw_err", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "recov_hw_err", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 28}], "config": {"lanes": 1, "fontsize": 10, "vspace": 140}}

Bits	Type	Reset	Name	Description
31:4				Reserved
3	wo	0x0	recov_hw_err	Write 1 to trigger one alert event of this kind.
2	wo	0x0	fatal_hw_err	Write 1 to trigger one alert event of this kind.
1	wo	0x0	recov_sw_err	Write 1 to trigger one alert event of this kind.
0	wo	0x0	fatal_sw_err	Write 1 to trigger one alert event of this kind.

SW_RECOV_ERR

Software recoverable error

Offset: 0x4
Reset default: 0x9
Reset mask: 0xf

Fields

{"reg": [{"name": "VAL", "bits": 4, "attr": ["rw"], "rotate": 0}, {"bits": 28}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:4				Reserved
3:0	rw	0x9	VAL	Software recoverable alert. When set to any value other than kMultiBitBool4False, a recoverable alert is sent. Once the alert is sent, the field is then reset to kMultiBitBool4False.

SW_FATAL_ERR

Software fatal error

Offset: 0x8
Reset default: 0x9
Reset mask: 0xf

Fields

{"reg": [{"name": "VAL", "bits": 4, "attr": ["rw1s"], "rotate": 0}, {"bits": 28}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:4				Reserved
3:0	rw1s	0x9	VAL	Software fatal alert. When set to any value other than kMultiBitBool4False, a fatal alert is sent. Note, this field once cleared cannot be set and will continuously cause alert events.

IBUS_REGWEN

Ibus address control regwen.

Reset default: 0x1
Reset mask: 0x1

Instances

Name	Offset
IBUS_REGWEN_0	0xc
IBUS_REGWEN_1	0x10

Fields

{"reg": [{"name": "EN", "bits": 1, "attr": ["rw0c"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name
31:1			Reserved
0	rw0c	0x1	EN

IBUS_REGWEN . EN

Ibus address controls write enable. Once set to 0, it can longer be configured to 1

Value	Name	Description
0x0	locked	Address controls can no longer be configured until next reset.
0x1	enabled	Address controls can still be configured.

IBUS_ADDR_EN

Enable Ibus address matching

Reset default: 0x0
Reset mask: 0x1

Instances

Name	Offset
IBUS_ADDR_EN_0	0x14
IBUS_ADDR_EN_1	0x18

Fields

{"reg": [{"name": "EN", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:1				Reserved
0	rw	0x0	EN	Enable ibus address matching.

IBUS_ADDR_MATCHING

Matching region programming for ibus.

The value programmed is done at power-of-2 alignment. For example, if the intended matching region is 0x8000_0000 to 0x8000_FFFF, the value programmed is 0x8000_7FFF.

The value programmed can be determined from the translation granule. Assume the user wishes to translate a specific 64KB block to a different address: 64KB has a hex value of 0x10000. Subtract 1 from this value and then right shift by one to obtain 0x7FFF. This value is then logically OR’d with the upper address bits that would select which 64KB to translate.

In this example, the user wishes to translate the 0x8000-th 64KB block. The value programmed is then 0x8000_7FFF.

If the user were to translate the 0x8001-th 64KB block, the value programmed would be 0x8001_7FFF.

Reset default: 0x0
Reset mask: 0xffffffff

Instances

Name	Offset
IBUS_ADDR_MATCHING_0	0x1c
IBUS_ADDR_MATCHING_1	0x20

Fields

{"reg": [{"name": "VAL", "bits": 32, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:0	rw	0x0	VAL	Matching region value

IBUS_REMAP_ADDR

The remap address after a match has been made. The remap bits apply only to top portion of address bits not covered by the matching region.

For example, if the translation region is 64KB, the remapped address applies only to the upper address bits that select which 64KB to be translated.

Reset default: 0x0
Reset mask: 0xffffffff

Instances

Name	Offset
IBUS_REMAP_ADDR_0	0x24
IBUS_REMAP_ADDR_1	0x28

Fields

{"reg": [{"name": "VAL", "bits": 32, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:0	rw	0x0	VAL	Remap addr value

DBUS_REGWEN

Dbus address control regwen.

Reset default: 0x1
Reset mask: 0x1

Instances

Name	Offset
DBUS_REGWEN_0	0x2c
DBUS_REGWEN_1	0x30

Fields

{"reg": [{"name": "EN", "bits": 1, "attr": ["rw0c"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name
31:1			Reserved
0	rw0c	0x1	EN

DBUS_REGWEN . EN

Ibus address controls write enable. Once set to 0, it can longer be configured to 1

Value	Name	Description
0x0	locked	Address controls can no longer be configured until next reset.
0x1	enabled	Address controls can still be configured.

DBUS_ADDR_EN

Enable dbus address matching

Reset default: 0x0
Reset mask: 0x1

Instances

Name	Offset
DBUS_ADDR_EN_0	0x34
DBUS_ADDR_EN_1	0x38

Fields

{"reg": [{"name": "EN", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:1				Reserved
0	rw	0x0	EN	Enable dbus address matching.

DBUS_ADDR_MATCHING

See IBUS_ADDR_MATCHING_0 for detailed description.

Reset default: 0x0
Reset mask: 0xffffffff

Instances

Name	Offset
DBUS_ADDR_MATCHING_0	0x3c
DBUS_ADDR_MATCHING_1	0x40

Fields

{"reg": [{"name": "VAL", "bits": 32, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:0	rw	0x0	VAL	Matching region value

DBUS_REMAP_ADDR

See IBUS_REMAP_ADDR_0 for a detailed description.

Reset default: 0x0
Reset mask: 0xffffffff

Instances

Name	Offset
DBUS_REMAP_ADDR_0	0x44
DBUS_REMAP_ADDR_1	0x48

Fields

{"reg": [{"name": "VAL", "bits": 32, "attr": ["rw"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:0	rw	0x0	VAL	Remap addr value

NMI_ENABLE

Enable mask for NMI. Once an enable mask is set, it cannot be disabled.

Offset: 0x4c
Reset default: 0x0
Reset mask: 0x3

Fields

{"reg": [{"name": "ALERT_EN", "bits": 1, "attr": ["rw1s"], "rotate": -90}, {"name": "WDOG_EN", "bits": 1, "attr": ["rw1s"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 100}}

Bits	Type	Reset	Name	Description
31:2				Reserved
1	rw1s	0x0	WDOG_EN	Enable mask for watchdog NMI
0	rw1s	0x0	ALERT_EN	Enable mask for alert NMI

NMI_STATE

Current NMI state

Offset: 0x50
Reset default: 0x0
Reset mask: 0x3

Fields

{"reg": [{"name": "ALERT", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "WDOG", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:2				Reserved
1	rw1c	0x0	WDOG	Current state for watchdog NMI
0	rw1c	0x0	ALERT	Current state for alert NMI

ERR_STATUS

error status

Offset: 0x54
Reset default: 0x0
Reset mask: 0x701

Fields

{"reg": [{"name": "REG_INTG_ERR", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 7}, {"name": "FATAL_INTG_ERR", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "FATAL_CORE_ERR", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"name": "RECOV_CORE_ERR", "bits": 1, "attr": ["rw1c"], "rotate": -90}, {"bits": 21}], "config": {"lanes": 1, "fontsize": 10, "vspace": 160}}

Bits	Type	Reset	Name	Description
31:11				Reserved
10	rw1c	0x0	RECOV_CORE_ERR	rv_core_ibex detected a recoverable internal error (`alert_minor` from Ibex seen)
9	rw1c	0x0	FATAL_CORE_ERR	rv_core_ibex detected a fatal internal error (`alert_major_internal_o` from Ibex seen)
8	rw1c	0x0	FATAL_INTG_ERR	rv_core_ibex detected a response integrity error
7:1				Reserved
0	rw1c	0x0	REG_INTG_ERR	rv_core_ibex_peri detected a register transmission integrity error

RND_DATA

Random data from EDN

Offset: 0x58
Reset default: 0x0
Reset mask: 0xffffffff

Fields

{"reg": [{"name": "DATA", "bits": 32, "attr": ["ro"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name
31:0	ro	0x0	DATA

RND_DATA . DATA

Random bits taken from the EDN. RND_STATUS.RND_DATA_VALID indicates if this data is valid. When valid, reading from this register invalidates the data and requests new data from the EDN. The register becomes valid again when the EDN provides new data. When invalid the register value will read as 0x0 with an EDN request for new data pending. Upon reset the data will be invalid with a new EDN request pending.

RND_STATUS

Status of random data in RND_DATA

Offset: 0x5c
Reset default: 0x0
Reset mask: 0x3

Fields

{"reg": [{"name": "RND_DATA_VALID", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "RND_DATA_FIPS", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 160}}

Bits	Type	Reset	Name	Description
31:2				Reserved
1	ro	0x0	RND_DATA_FIPS	When `RND_STATUS.RND_DATA_VALID` is 1, this bit indicates whether `RND_DATA` is fips quality. When `RND_STATUS.RND_DATA_VALID` is 0, this bit has no meaning.
0	ro	0x0	RND_DATA_VALID	When set, the data in `RND_DATA` is valid. When clear an EDN request for new data for `RND_DATA` is pending.

FPGA_INFO

FPGA build timestamp info. This register only contains valid data for fpga, for all other variants it is simply 0.

Offset: 0x60
Reset default: 0x0
Reset mask: 0xffffffff

Fields

{"reg": [{"name": "VAL", "bits": 32, "attr": ["ro"], "rotate": 0}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:0	ro	0x0	VAL	FPGA build timestamp information.

DV_SIM_WINDOW

Exposed tlul window for DV only purposes.

Word Aligned Offset Range: 0x80to0x9c
Size (words): 8
Access: rw
Byte writes are supported.