imx283--read cpu unique id

[志明李]

Hello Forum:

Today,I tried to read imx283's cpu unique identifitcation,then i found some registers by reading the imx28 datasheet(chapter 19.4.38&chapter 19.4.39),and i read the register(HW_DIGCTL_CHIPID):

unsigned long reg;

reg = __raw_readl(IO_ADDRESS(DIGCTL_PHYS_ADDR)+0x310);

printk("%s: 0x%x\n", __func__, reg);

It returns 0x28000001，like as described in the manual.

I tried another register(HW_DIGCTL_FSL):

unsigned long reg;

reg = __raw_readl(IO_ADDRESS(DIGCTL_PHYS_ADDR)+0x300);

printk("%s: 0x%x\n", __func__, reg);

ok,it's copyright,returns 65657246.

These  don't seem like a unique identifier,any other idea?

THX:smileyhappy:

[Yuri · Accepted solution]

The following forum item may be useful :

https://community.freescale.com/message/297846#297846

In particular, values in registers HW_OCOTP_OPS2 (at 0x8002_C150 address) and

HW_OCOTP_UN2 (0x8002_C190) relate to the ID.

Please take a look at sections 20.4.22 [Value of OTP Bank2 Word3 (Freescale

OPS2) (HW_OCOTP_OPS2)] and 20.4.26 [Value of OTP Bank2 Word7 (Unassigned2)

(HW_OCOTP_UN2)] of the i.MX28 Reference Manual.

Next, please pay attention :

OTP banks must be open through HW_OCOTP_CTRL[RD_BANK_OPEN] before reading this

register. Reading this register without having HW_OCOTP_CTRL[RD_BANK_OPEN] set

and HW_OCOTP_CTRL[BUSY] clear, will result in HW_OCOTP_CTRL[ERROR] being set and

0xBADA_BADA being returned.

Also please look at section 20.2.1 (Software Read Sequence) for more details.