41.6.2.4 Counter Mode
The Counter mode is selected by the Mode bit group in the Control A register (CTRLA.MODE). By default, the counter is enabled in the 16-bit counter resolution. Three counter resolutions are available:
- COUNT8 – The 8-bit TC has its own Period Value and Period Buffer Value registers (PER and PERBUF).
- COUNT16 – 16-bit is the default Counter mode. There is no dedicated period register in this mode.
- COUNT32 – 32-bit mode is achieved by pairing two
16-bit TC peripherals.
When paired, the TC peripherals are configured using the registers of the even-numbered TC (TC0, TC2, TC4, TC6 or TC8 respectively).
The TC bus clocks (CLK_TCx_APB) for both host and client TCs need to be enabled.
The odd-numbered partner (TC1, TC3, TC5, TC7 or TC9, respectively) acts as a client, and the Client bit in the Status register (STATUS.SLAVE) is set. The register values of a client will not reflect the registers of the 32-bit counter. Writing to any of the slave registers will not affect the 32-bit counter. Normal access to the slave COUNT and CCx registers is not allowed.