TMS320C6678: Supervisor mode and User mode

Cherry Zhou

Part Number: TMS320C6678
Other Parts Discussed in Thread: SYSBIOS

Hi Team,

The customer is looking for a use case for TMS320C66x in User mode.

User and privilege modes are mentioned in TMS320C66x DSP CorePac for memory protection:

1) As stated above, the operating system kernel and hardware device drivers are run in privilege mode, and the vocoders and terminal applications are run in User mode. Could you help share an example in this case?

2) Also, assuming that SYS/BIOS or Linux operating system is installed on the C66x, are user tasks (such as lights, computing tasks) running on the operating system running in User mode?

3) In addition to the instruction set, the description of Supervisor mode and User mode is mentioned in the relevant sections of basically Memory Protection (MPC) in other documents, and can it be understood that the privileged and user modes are proposed for memory protection purposes?

Could you help check this case? Thanks.

Best Regards,

Cherry

over 1 year ago

0 Shankari G over 1 year ago

TI__Mastermind 25535 points

Cherry,

https://www.ti.com/lit/ug/sprugw5a/sprugw5a.pdf

Are you referring this doc for memory protection?

If no, point me the doc, you are referring to....

Regards

Shankari G

0 Cherry Zhou over 1 year ago in reply to Shankari G

TI__Mastermind 22235 points

Hi Shankari G,

Thank you for the support.

Please see the Section 10 of the following paper:

C66x CorePac User's Guide (Rev. C) (ti.com.cn)

Thanks and regards,

Cherry

0 Shankari G over 1 year ago in reply to Cherry Zhou

TI__Mastermind 25535 points

Cherry,

OK.

My answers below.

Cherry Zhou said:
1) As stated above, the operating system kernel and hardware device drivers are run in privilege mode, and the vocoders and terminal applications are run in User mode. Could you help share an example in this case?

For example, In C6678, the latest SDK, PROCESSOR-SDK-RTOS-C667x 06_03_00_106, these 56 examples are user mode. The SYSBIOS is the supervisor mode.

Cherry Zhou said:
2) Also, assuming that SYS/BIOS or Linux operating system is installed on the C66x, are user tasks (such as lights, computing tasks) running on the operating system running in User mode?

It depends. One has to either go through the "Memory protection settings" of the code as per this doc:- https://www.ti.com/lit/ug/sprugw5a/sprugw5a.pdf

Our TI offerings are ----- Only SYSBIOS for C66x. No Linux on C66x. Linux is for ARM core. As you already know, C66x is DSP only-core.

Cherry Zhou said:
3) In addition to the instruction set, the description of Supervisor mode and User mode is mentioned in the relevant sections of basically Memory Protection (MPC) in other documents, and can it be understood that the privileged and user modes are proposed for memory protection purposes?

Yes.

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FOR C6678 - memory protection, we should follow this doc: https://www.ti.com/lit/ug/sprugw5a/sprugw5a.pdf

https://www.ti.com.cn/cn/lit/ug/sprugw0c/sprugw0c.pdf -- This one is a generic one for all C66xx.

For C6678, we have to follow the device-specific one.

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Regards

Shankari G

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TMS320C6678: Supervisor mode and User mode