[21] NVMC: Disabling instruction cache causes skip of next instruction

Symptoms

The CPU skips first instruction after instruction cache is disabled.

Conditions

The code executes instructions to disable the instruction cache.

Consequences

The program does not execute as expected.

Workaround

 

_attribute_((aligned(ICACHE_LINE_SIZE)))

void icache_disable(void) {
    int key = DisableInterrupts(); 
    __ISB(); 
    NRF_NVMC->ICACHECNF = 0; 
    __ISB(); 
    EnableInterrupts(key);
}