[89] TWI: Static 400 µA current while using GPIOTE

This anomaly applies to IC Rev. Rev 1, build codes QFAA-B00, QFAB-B00, CIAA-B00.

It was inherited from the previous IC revision Engineering C.

Symptoms

Static current consumption between 400 µA to 450 µA when using TWI in combination with GPIOTE.

Conditions

  • GPIOTE is configured in event mode
  • TWI utilizes EasyDMA

Consequences

Current consumption higher than specified

Workaround

Turn the TWI off and back on after it has been disabled. To do so: If TWI0 is used,
 
*(volatile uint32_t *)0x40003FFC = 0;
*(volatile uint32_t *)0x40003FFC;
*(volatile uint32_t *)0x40003FFC = 1;
If TWI1 is used,
 
*(volatile uint32_t *)0x40004FFC = 0;
*(volatile uint32_t *)0x40004FFC;
*(volatile uint32_t *)0x40004FFC = 1;
write 0 followed by a 1 to the POWER register (address 0xFFC) of the TWI that needs to be disabled. Reconfiguration of TWI is required before next usage.