22.3.3.4 Synchronized with Timer/Counter Type A

The TCB can be configured to use the clock (CLK_TCA) of a Timer/Counter type A (TCAn) by writing to the Clock Select bit field (CLKSEL) in the Control A register (TCBn.CTRLA). In this setting, the TCB will count on the exact same clock source as selected in TCAn.

When the Synchronize Update (SYNCUPD) bit in the Control A (TCBn.CTRLA) register is written to ‘1’, the TCB counter will restart when the TCAn counter restarts.