[SOLVED] JLINK_CORESIGHT_WriteDP parameter

Masmiseim · Dec 8th 2020, 11:16am

Hello Segger Team,

I try to understand a JinkScript for the iMXRT685 which comes with the SDK from NXP.

They call JLINK_CORESIGHT_WriteDP like this:

Source Code

JLINK_CORESIGHT_WriteDP(2, 0x020000f0);

According your documentation, the first parameter can be one of

JLINK_CORESIGHT_DP_REG_IDCODE
JLINK_CORESIGHT_DP_REG_ABORT
JLINK_CORESIGHT_DP_REG_CTRL_STAT
JLINK_CORESIGHT_DP_REG_SELECT
JLINK_CORESIGHT_DP_REG_RDBUF
JLINK_CORESIGHT_AP_REG_CTRL
JLINK_CORESIGHT_AP_REG_ADDR
JLINK_CORESIGHT_AP_REG_DATA
JLINK_CORESIGHT_AP_REG_BD0
JLINK_CORESIGHT_AP_REG_BD1
JLINK_CORESIGHT_AP_REG_BD2
JLINK_CORESIGHT_AP_REG_BD3
JLINK_CORESIGHT_AP_REG_ROM
JLINK_CORESIGHT_AP_REG_IDR

Which of those constants is related to the Index two?

Thanks and regards

SEGGER - Fabian · Dec 10th 2020, 10:05am

Hi,
Thank you for your inquiry.

Usually, this would be JLINK_CORESIGHT_DP_REG_SELECT.

Best regards,
Fabian

Masmiseim · Dec 10th 2020, 10:36am

Hello Fabian,

thank you for your feedback.

What do you mean with usually? Is this dependent to the used controller?

NXP is using ‘JLINK_CORESIGHT_WriteDP’ regular with a number instead of the symbolic constants, therefore is it possible to get a full list with the relates indices?

Thanks, and best regards

SEGGER - Fabian · Dec 10th 2020, 1:34pm

Hi,
Sorry this was a Typo.

For DP, RegIndex "2" is always JLINK_CORESIGHT_DP_REG_SELECT.

RegIndex specifies the index of the DP register.
The DP registers and the related indexes are documented by ARM.
Currently you would have to look them up in the ARM documentation.

I will check internally if we want to add the define values to the documentation.

Best regards,
Fabian

Masmiseim · Dec 10th 2020, 1:50pm

Hello Fabian,

the Indexes you are using for JLINK_CORESIGHT_WriteDP seems not to be related to the addresses of the registers which you can find in the ARM specification.
Compare developer.arm.com/documentatio…tation-specific-registers

The Register Addresses are

Address	Read	Write
0x00	IDCODE	ABORT
0x04	CTRL/STAT	CTRL/STAT
0x08	RESEND	SELECT
0x0C	RDBUFF	N/A

Therefore, it would be good to have the values in the documentation

Best regards

SEGGER - Fabian · Dec 10th 2020, 4:01pm

Hi,
That is why I did not write "Address" but "Index".

Address / 4 = Address or:
Index * 0x4 = Address =>
For Write:
Index 0 => 0x0 ABORT
Index 1 => 0x4 CTRL/STAT
Index 2 => 0x8 SELECT
Index 3 => N/A

Best regards,
Fabian

Masmiseim · Dec 11th 2020, 8:37am

Hello Fabian,

thanks for the Update.

ARM is only referring to the Address in the documentation. Segger is using an Index. The correlation between both was unclear to me.

Best Regards

SEGGER - Fabian · Dec 11th 2020, 4:19pm

Hi,
This is very understandable.
I am sorry for not being clear enough.

Do you have any further questions regarding this?

Best regards,
Fabian

Masmiseim · Dec 14th 2020, 12:25pm

Hello Fabian,
no further questions, thank you
Best regards

SEGGER - Fabian · Dec 16th 2020, 9:09am

Hi,

We will close this thread now.

Best regards,
Fabian

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