18.4.9 User Unique ID

The User ID is a 16-bit ID that may be programmed to differentiate products that use the same device. The User ID value may be read directly out of the USER_ID register or through the JTAG interface via the MCHP_CMD.USER ID command.

There is no dedicated JTAG status bit to indicate when the User ID value is loaded into the USER_ID register and is ready to be read from JTAG. It is assumed that a non-zero value for the User ID will be used to indicate that the User ID is loaded.

The USER_ID register is reset on power-up, then is loaded with trusted data from FBCFG5 during the pre-boot period and it is controlled.

Trusted data from Flash means when there is no BCFG* fail status during Flash configuration word reads. If accompanied by fail status or blank/erase indication, then Reset values (described in the register description below) are retained and new values from FBCFG5 are not loaded.

Name:	USER_ID
Offset:	0xA0
Reset:	0x00
Property:	-


Bit	31	30	29	28	27	26	25	24

Access
Reset


Bit	23	22	21	20	19	18	17	16

Access
Reset


Bit	15	14	13	12	11	10	9	8
	USER_ID[15:8]
Access	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	USER_ID[7:0]
Access	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L	R/W/L
Reset	0	0	0	0	0	0	0	0

Bits 15:0 – USER_ID[15:0] User unique ID, readable using the JTAG USER_ID instruction

Note: This field is only writable when CFGLOCK[1:0] = 00.