Registers

The RoT shall define three registers and drive the debug policy bus from that. These registers are updated by the RoT FW and are distributed by the debug policy bus to all consumers, e.g., HW TAPs in the system. Depending on the configured debug category, a consumer might accept the debug command or not (if it is not part of the selected debug category).

Summary of the `core` interface’s registers

Name	Offset	Length	Description
soc_dbg_ctrl.`ALERT_TEST`	0x0	4	Alert Test Register
soc_dbg_ctrl.`DEBUG_POLICY_VALID_SHADOWED`	0x4	4	Debug Policy Valid.
soc_dbg_ctrl.`DEBUG_POLICY_CATEGORY_SHADOWED`	0x8	4	Debug Policy category
soc_dbg_ctrl.`DEBUG_POLICY_RELOCKED`	0xc	4	Debug Policy relocked
soc_dbg_ctrl.`TRACE_DEBUG_POLICY_CATEGORY`	0x10	4	Trace register to observe the debug category that is determined either by hardware or by software.
soc_dbg_ctrl.`TRACE_DEBUG_POLICY_VALID_RELOCKED`	0x14	4	Trace register to observe the valid or relocked state that is determined either by hardware or by software.
soc_dbg_ctrl.`STATUS`	0x18	4	Debug Status Register

ALERT_TEST

Alert Test Register

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

Fields

{"reg": [{"name": "fatal_fault", "bits": 1, "attr": ["wo"], "rotate": -90}, {"name": "recov_ctrl_update_err", "bits": 1, "attr": ["wo"], "rotate": -90}, {"bits": 30}], "config": {"lanes": 1, "fontsize": 10, "vspace": 230}}

Bits	Type	Reset	Name	Description
31:2				Reserved
1	wo	0x0	recov_ctrl_update_err	Write 1 to trigger one alert event of this kind.
0	wo	0x0	fatal_fault	Write 1 to trigger one alert event of this kind.

DEBUG_POLICY_VALID_SHADOWED

Debug Policy Valid. Once valid is set to Mubi4::True, the debug policy cannot be written anymore.

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

Fields

{"reg": [{"name": "debug_policy_valid", "bits": 4, "attr": ["rw1s"], "rotate": -90}, {"bits": 28}], "config": {"lanes": 1, "fontsize": 10, "vspace": 200}}

Bits	Type	Reset	Name	Description
31:4				Reserved
3:0	rw1s	0x9	debug_policy_valid	Indicates the validity of the debug policy output.

DEBUG_POLICY_CATEGORY_SHADOWED

Debug Policy category

Offset: 0x8
Reset default: 0x50
Reset mask: 0x7f

Fields

{"reg": [{"name": "debug_policy_category", "bits": 7, "attr": ["rw"], "rotate": -90}, {"bits": 25}], "config": {"lanes": 1, "fontsize": 10, "vspace": 230}}

Bits	Type	Reset	Name	Description
31:7				Reserved
6:0	rw	0x50	debug_policy_category	Debug Policy Control Setting. Indicates the current debug authorization policy that is distributed to the rest of the SoC to govern debug / DFT feature unlock.

DEBUG_POLICY_RELOCKED

Debug Policy relocked

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

Fields

{"reg": [{"name": "debug_policy_relocked", "bits": 4, "attr": ["rw"], "rotate": -90}, {"bits": 28}], "config": {"lanes": 1, "fontsize": 10, "vspace": 230}}

Bits	Type	Reset	Name	Description
31:4				Reserved
3:0	rw	0x9	debug_policy_relocked	The relocked state.

TRACE_DEBUG_POLICY_CATEGORY

Trace register to observe the debug category that is determined either by hardware or by software.

Offset: 0x10
Reset default: 0x50
Reset mask: 0x7f

Fields

{"reg": [{"name": "category", "bits": 7, "attr": ["ro"], "rotate": 0}, {"bits": 25}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:7				Reserved
6:0	ro	0x50	category	The debug policy determined by hardware or software.

TRACE_DEBUG_POLICY_VALID_RELOCKED

Trace register to observe the valid or relocked state that is determined either by hardware or by software.

Offset: 0x14
Reset default: 0x99
Reset mask: 0xff

Fields

{"reg": [{"name": "valid", "bits": 4, "attr": ["ro"], "rotate": 0}, {"name": "relocked", "bits": 4, "attr": ["ro"], "rotate": -90}, {"bits": 24}], "config": {"lanes": 1, "fontsize": 10, "vspace": 100}}

Bits	Type	Reset	Name	Description
31:8				Reserved
7:4	ro	0x9	relocked	The relocked state determined by hardware or software.
3:0	ro	0x9	valid	The valid state determined by hardware or software.

STATUS

Debug Status Register

Offset: 0x18
Reset default: 0x0
Reset mask: 0xf1

Fields

{"reg": [{"name": "auth_debug_intent_set", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 3}, {"name": "auth_window_open", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "auth_window_closed", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "auth_unlock_success", "bits": 1, "attr": ["rw"], "rotate": -90}, {"name": "auth_unlock_failed", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 24}], "config": {"lanes": 1, "fontsize": 10, "vspace": 230}}

Bits	Type	Reset	Name	Description
31:8				Reserved
7	rw	0x0	auth_unlock_failed	Status bit indicating whether the unlock protocol resulted in unlock failure at the requested level.
6	rw	0x0	auth_unlock_success	Status bit indicating whether the unlock protocol resulted in a successful unlock at the requested level.
5	rw	0x0	auth_window_closed	Status bit that indicates that SoC reset sequence is unpaused. SoC shall continue to boot and the debug authorization exchange cannot take place anymore until the next reset. Note that the rest of the SoC reset sequence is triggered by the OT RoT.
4	rw	0x0	auth_window_open	Status bit that tells whether debug authorization exchange can take place. This bit is set when auth_debug_intent_set is 1, and the SoC reset sequence is paused to enable debug authorization exchange.
3:1				Reserved
0	rw	0x0	auth_debug_intent_set	Status bit indicating whether the debug intent hardware strap was set. If set, SoC will be treated as under debug, and authorized debug can be enabled to unlock the SoC at the desired debug unlock level.

Summary of the `jtag` interface’s registers

Name	Offset	Length	Description
soc_dbg_ctrl.`JTAG_TRACE_DEBUG_POLICY_CATEGORY`	0x0	4	Trace register to observe the debug category that is determined either by hardware or by software.
soc_dbg_ctrl.`JTAG_TRACE_DEBUG_POLICY_VALID_RELOCKED`	0x4	4	Trace register to observe the valid or relocked state that is determined either by hardware or by software.
soc_dbg_ctrl.`JTAG_CONTROL`	0x8	4	JTAG control register to interact with the boot flow.
soc_dbg_ctrl.`JTAG_STATUS`	0xc	4	Debug Status Register
soc_dbg_ctrl.`JTAG_BOOT_STATUS`	0x10	4	Debug boot status register that tells important boot state information.
soc_dbg_ctrl.`JTAG_TRACE_SOC_DBG_STATE`	0x14	4	Reports the current debug state coming from OTP.

JTAG_TRACE_DEBUG_POLICY_CATEGORY

Trace register to observe the debug category that is determined either by hardware or by software.

Offset: 0x0
Reset default: 0x50
Reset mask: 0x7f

Fields

{"reg": [{"name": "category", "bits": 7, "attr": ["ro"], "rotate": 0}, {"bits": 25}], "config": {"lanes": 1, "fontsize": 10, "vspace": 80}}

Bits	Type	Reset	Name	Description
31:7				Reserved
6:0	ro	0x50	category	The debug policy determined by hardware or software.

JTAG_TRACE_DEBUG_POLICY_VALID_RELOCKED

Trace register to observe the valid or relocked state that is determined either by hardware or by software.

Offset: 0x4
Reset default: 0x99
Reset mask: 0xff

Fields

{"reg": [{"name": "valid", "bits": 4, "attr": ["ro"], "rotate": 0}, {"name": "relocked", "bits": 4, "attr": ["ro"], "rotate": -90}, {"bits": 24}], "config": {"lanes": 1, "fontsize": 10, "vspace": 100}}

Bits	Type	Reset	Name	Description
31:8				Reserved
7:4	ro	0x9	relocked	The relocked state determined by hardware or software.
3:0	ro	0x9	valid	The valid state determined by hardware or software.

JTAG_CONTROL

JTAG control register to interact with the boot flow.

Offset: 0x8
Reset default: 0x0
Reset mask: 0x1

Fields

{"reg": [{"name": "boot_continue", "bits": 1, "attr": ["rw"], "rotate": -90}, {"bits": 31}], "config": {"lanes": 1, "fontsize": 10, "vspace": 150}}

Bits	Type	Reset	Name	Description
31:1				Reserved
0	rw	0x0	boot_continue	JTAG bit to stop or continue the boot flow of Ibex. 1’b0: Stop and halt boot flow. 1’b1: Continue with the boot flow and let Ibex fetch code.

JTAG_STATUS

Debug Status Register

Offset: 0xc
Reset default: 0x0
Reset mask: 0xf1

Fields

{"reg": [{"name": "auth_debug_intent_set", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 3}, {"name": "auth_window_open", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "auth_window_closed", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "auth_unlock_success", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "auth_unlock_failed", "bits": 1, "attr": ["ro"], "rotate": -90}, {"bits": 24}], "config": {"lanes": 1, "fontsize": 10, "vspace": 230}}

Bits	Type	Reset	Name	Description
31:8				Reserved
7	ro	0x0	auth_unlock_failed	Status bit indicating whether the unlock protocol resulted in unlock failure at the requested level
6	ro	0x0	auth_unlock_success	Status bit indicating whether the unlock protocol resulted in a successful unlock at the requested level
5	ro	0x0	auth_window_closed	Status bit that indicates that SoC reset sequence is unpaused. SoC shall continue to boot and the debug authorization exchange cannot take place anymore until the next reset. Note that the rest of the SoC reset sequence is triggered by the OT RoT.
4	ro	0x0	auth_window_open	Status bit that tells whether debug authorization exchange can take place. This bit is set when auth_debug_intent_set is 1, and the SoC reset sequence is paused to enable debug authorization exchange.
3:1				Reserved
0	ro	0x0	auth_debug_intent_set	Status bit indicating whether the debug intent hardware strap was set. If set, SoC will be treated as under debug, and authorized debug can be enabled to unlock the SoC at the desired debug unlock level.

JTAG_BOOT_STATUS

Debug boot status register that tells important boot state information. Note that this information is reflected only if the hw_dft_en signal is true.

Offset: 0x10
Reset default: 0x0
Reset mask: 0x1ffff

Fields

{"reg": [{"name": "main_clk_status", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "io_clk_status", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "otp_done", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "lc_done", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "cpu_fetch_en", "bits": 1, "attr": ["ro"], "rotate": -90}, {"name": "halt_fsm_state", "bits": 6, "attr": ["ro"], "rotate": -90}, {"name": "boot_greenlight_done", "bits": 3, "attr": ["ro"], "rotate": -90}, {"name": "boot_greenlight_good", "bits": 3, "attr": ["ro"], "rotate": -90}, {"bits": 15}], "config": {"lanes": 1, "fontsize": 10, "vspace": 220}}

Bits	Type	Reset	Name	Description
31:17				Reserved
16:14	ro	0x0	boot_greenlight_good	Green lights status for the boot process: good indication coming from [0]: base ROM [1]: second ROM [2]: this module
13:11	ro	0x0	boot_greenlight_done	Green lights for the boot process: done indication coming from [0]: base ROM [1]: second ROM [2]: this module Note that for the boot process to go through, all done bits in this field and all good bits in the next field need to be set.
10:5	ro	0x0	halt_fsm_state	The state of the halt FSM.
4	ro	0x0	cpu_fetch_en	Indication from power manager to IBEX to start code execution
3	ro	0x0	lc_done	Lifecycle controller initialization done; LC policy is decoded and set.
2	ro	0x0	otp_done	OTP controller initialization complete.
1	ro	0x0	io_clk_status	Status of the IO Clock activation.
0	ro	0x0	main_clk_status	Status of the main clock activation.

JTAG_TRACE_SOC_DBG_STATE

Reports the current debug state coming from OTP. Note that this information is reflected only if the hw_dft_en signal is true.

Offset: 0x14
Reset default: 0x0
Reset mask: 0xffffffff

Fields

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

Bits	Type	Reset	Name	Description
31:0	ro	0x0	soc_dbg_state	The current debug state.