J721S2XSOMXEVM: Issue Accessing MCU Timer Register Space

Hi Madhusudan Gupta,

Hi,

1) Are you using SBL for this image, If yes, from where I can download and use it, because I tried with sample code also, it is throwing same exception.

2) What are your switch settings like SW3, SW8, SW9, SW13

With Regards,

Madhusudan Gupta

Hi Madhusudan Gupta,

I am not using the SBL for this test. I am executing the .xer5f binary file directly through CCS, and the device is configured in No Boot mode.

https://software-dl.ti.com/jacinto7/esd/processor-sdk-rtos-j721s2/latest/exports/docs/psdk_rtos/docs/user_guide/evm_setup_j721s2.html 

The switch settings I am using are:

SW8[1–8]: 1000 1000
SW9[1–8]: 0111 0000
SW3[1–8]: 0xxx xxxx

Regards,

Karthik

Hi,

It seems, MCU Timer is guarded by TIFS.

To access them ownership needs to be transferred to R5 Core instead of SYSFW, What do you think ?

With Regards,

Madhusudan Gupta

Hello,

FYI, We tried to enable it from firewall by writing following register and succeeded for MAIN Timer 0 -7, but not for MCU Timer peripherals.

 A) CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_control  (0x45108000)  --   0x30A

After writing 0x30A to the above register, the issue explained earlier in the description is 1 no longer occurred, and we were able to see the memory in dump.

We then attempted the steps below to obtain read/write access, but were unsuccessful.

 B) CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_permission_0 (0x45108004)  --  0x60FFFF

We considered 0x60 for bit 16:23, as priv_id for MCU Core0 is 96 (0x60)

 C) CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_permission_1 (0x45108008)  --  0x60FFFF

 D) CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_permission_2 (0x4510800C)  --  0x60FFFF

 E) CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_start_address_l,

CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_start_address_h,

CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_end_address_l,

CBASS_FW_Idmtimer_dmc1ms_mcu_0_timer_cfg_vbp_fw_region_0_end_address_h

were already having appropriate values as per MCU_Timer0 memory range i.e. 0x40400000 -- 0x40400FFF

After this we attempted to write to the MCU_Timer peripheral address range to start the timer, but encountered exception as explained in the description because the memory region remained protected.

Note: We got the access of MAIN Domain Timer 0 – 7, by following these steps mentioned in point A - E.

          I am looking forward to access MCU Domain Timer memory range and we don’t want to use SBL APIs, rather I am expecting register level details.

Hi Madhusudan Gupta,

Could you please let me know whether there is a specific timer register that can be accessed from the MCU domain? If so, could you kindly provide the corresponding register address?

Regards,

Karthik

Hi Karthikeyan,

There are 10 Timers in MCU domain MCU Timer0-9, I am trying to access all of them at different locations for different purposes.

I am not getting access to any of them.

Timer register details can found in excel sheet at following location
https://www.ti.com/lit/zip/spruj28

FYR,

MCU Timer0 address range starting from 0x40400000 - 0x4040006F

MCU Timer1 address range starting from 0x40410000 - 0x4041006F

You can simply follow this schema (0x404<TimerID>0000 - 0x404<TimerID>006F) to calculate MCU Timer peripheral address range.

With Regards,

Madhusudan Gupta

Hi,

Thank you for sharing the details .I will try on my end and get back to you.

Regards,

Karthik

Hi Madhusudan Gupta,

I am able to access the MCU Timer0 and Timer1 registers directly at the register level. Please note that some timer registers or specific bits are read-only, so writes will not take effect. Make sure to access only the writable fields in each timer register and avoid writing to any reserved bits, as reserved fields are undefined and may cause unexpected behavior.

Timer0_Access.zip

Regards,

Karthik

I totally understand about R/O or R/W access specifiers for the registers.

I am trying to write 1 on CFG_TCLR.ST bit which is a R/W bit, and facing these explained issues.

Hi Madhusudan Gupta,

I am able to access the ST bit in the TIMER_TCLR register (0x40400038) as mentioned earlier. Could you please let me know how you are attempting to access this register? Are you using any driver example for this, and which boot mode are you using? If possible, could you also share your code?

Regards,

Karthik