efuse_guard

Check program and read targets against field locks, lifecycle-state rules, and RMA token checks.

HAS_LC_STATE distinguishes SEP (lifecycle field present) from SMC. LC_STATE_BIT_POSITION and TOKEN_MATCH_CODE locate and encode token checks; the SIP and chiplet token bit addresses are LC_STATE_BIT_POSITION+1 and +2.

The program and read interfaces sample the lock and secure-TM status when firmware starts a command and refuse a blocked start without issuing it; a command already issued completes.

efuse_err_o sets on a lock-refused start and sticks until error_clear_i.
Lock and secure-TM status are exported.

Parameters

Table 1. Parameters
Name	Type	Default	Description
`EFUSE_FIELDS`	`int unsigned`	`1`	eFuse field-map entry count.
`EFUSE_ADDR_WIDTH`	`int unsigned`	`12`	eFuse byte-address width.
`HAS_LC_STATE`	`bit`	`1'b0`	Set for SEP: exempts field index 0 from locks and gates the RMA token bits on token matches; clear for SMC.
`LC_STATE_BIT_POSITION`	`int unsigned`	`0`	Bit address of the lifecycle-state field.
`TOKEN_MATCH_CODE`	`logic [5:0]`	`6'b010101`	Token-match status code that permits programming the corresponding RMA token bit.
`SipTokenBitAddr`	`efuse_addr_t`	`efuse_addr_t'(LC_STATE_BIT_POSITION + 1)`	Bit address of the RMA SiP token bit.
`ChipletTokenBitAddr`	`efuse_addr_t`	`efuse_addr_t'(LC_STATE_BIT_POSITION + 2)`	Bit address of the RMA chiplet token bit.

Ports

Table 2. Ports
Name	Direction	Type	Description
`clk_i`	input	`logic`	System clock.
`rst_ni`	input	`logic`	Active-low synchronous reset; clears efuse_err_o.
`secure_tm_i`	input	`logic`	Secure test mode, active-high; blocks every start without raising the error.
`efuse_field_map_i`	input	`efuse_pkg::rule_t [EFUSE_FIELDS-1:0]`	Per-field byte ranges and lock indices used to find the lock bits for a target address.
`rma_sip_token_match_i`	input	`logic [5:0]`	RMA SiP token-match status code from token processing.
`rma_chiplet_token_match_i`	input	`logic [5:0]`	RMA chiplet token-match status code from token processing.
`efuse_err_o`	output	`logic`	Sticky error set when a program or read start is refused by a lock or, for a program, by a missing RMA token match; not set by secure test mode.
`error_clear_i`	input	`logic`	Clears the sticky error; a same-cycle new error takes priority.
`shadow_regs_i`	input	`efuse_map_t`	Shadow eFuse map supplying the per-field read and write lock bits.
`program_target_addr_i`	input	`efuse_addr_t`	Fuse bit address a program start would target.
`read_target_addr_i`	input	`efuse_addr_t`	Fuse bit address a read start would target.
`program_blocked_i`	input	`logic`	One-cycle pulse: a lock refused a program start.
`read_blocked_i`	input	`logic`	One-cycle pulse: a lock refused a read start.
`is_read_locked_o`	output	`logic`	High when the read target address falls in a read-locked field.
`is_program_locked_o`	output	`logic`	High when the program target address is write locked or is an RMA token bit without a token match.
`secure_tm_blocked_o`	output	`logic`	High while secure test mode blocks fuse command starts.