# CTRLA

Control A

0x00 8 - 0x00

## Control A

 Bit 7 6 5 4 3 2 1 0 RUNSTDBY CASCADE SYNCUPD CLKSEL[2:0] ENABLE Access R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0

## Bit 6 – RUNSTDBY: Run Standby

Run Standby

Writing a ‘1’ to this bit will enable the peripheral to run in Standby sleep mode.

Writing this bit to ‘1’ enables cascading of two 16-bit Timer/Counters type B (TCBn) for 32-bit operation using the Event System. This bit must be ‘1’ for the timer/counter used for the two Most Significant Bytes (MSB). When this bit is ‘1’, the selected event source for capture (CAPT) is delayed by one peripheral clock cycle. This compensates the carry propagation delay when cascading two counters via the Event System.

## Bit 4 – SYNCUPD: Synchronize Update

Synchronize Update

When this bit is written to ‘1’, the TCB will restart whenever TCAn is restarted or overflows. This can be used to synchronize capture with the PWM period. If TCAn is selected as the clock source, the TCB will restart when that TCAn is restarted. For other clock selections, it will restart together with TCA0.

## Bits 3:1 – CLKSEL[2:0]: Clock Select

Clock Select

Writing these bits selects the clock source for this peripheral.
Value Name Description
0x0 DIV1 CLK_PER
0x1 DIV2 CLK_PER / 2
0x2 TCA0 Use CLK_TCA from TCA0
0x3-0x6 - Reserved
0x7 EVENT Positive edge on event input

## Bit 0 – ENABLE: Enable

Enable

Writing this bit to ‘1’ enables the Timer/Counter type B peripheral.