SoftDevice call stack in s132_nrf52_7.0.1

[oleg_krv]

The s132_nrf52_7.0.1 documentation says:

Call stack: The SoftDevice uses a call stack combined with the application. The worst-case stack usage for the SoftDevic e is 1.5 kB (0x600 bytes). A pplication writers should ensure that enough stack space is reserved to cover the worst-case SoftDevice call stack usage combined with the worst-case application call stack usage.

Does this mean that if I use the OS, then should every task have a margin on the stack to bind SoftDevice interrupts? Or only threads where functions from SoftDevice are called?

[oleg_krv]

https://infocenter.nordicsemi.com/topic/sds_s132/SDS/s1xx/mem_usage/mem_resource_map_usage.html

The application configures the call stack, and the MSP gets initialized on reset to the address specified by the application vector table entry 0. In its reset vector the application may configure the CPU to use the Process Stack Pointer (PSP) in thread mode. This configuration is optional but may be required by an OS, for example, to isolate application threads and OS context memory. The application programmer must be aware that the SoftDevice will use the MSP as it is always executed in exception mode.

[ovrebekk]

Hi 

According to this article if you use the PSP for your OS then you need to reserve 8 words (32 bytes) of overhead for the switch from thread mode to interrupt mode, but that is all. 

The rest of the SoftDevice stack usage would be put on the MSP stack. 

Best regards
Torbjørn