40.7.2 Control B Clear
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | CTRLBCLR |
| Offset: | 0x04 |
| Reset: | 0x00 |
| Property: | RW |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| CMD[2:0] | IDXCMD[1:0] | ONESHOT | LUPD | DIR | |||||
| Access | |||||||||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bits 7:5 – CMD[2:0] TCC Command
These bits can be used for software control of re-triggering and stop commands of the TCC. When a command has been executed, the CMD bit field will read back zero. The commands are executed on the next prescaled GCLK_TCCx clock cycle.
Writing zero to this bit group has no effect.
Writing a '1' to any of these bits will clear the pending command.
| Value | Name | Description |
|---|---|---|
| 0 | NONE | No action |
| 1 | RETRIGGER | Clear start, restart or retrigger |
| 2 | STOP | Force stop |
| 3 | UPDATE | Force update or double buffered registers |
| 4 | READSYNC | Force COUNT read synchronization |
| 5 | DMAOS | One-shot DMA trigger |
Bits 4:3 – IDXCMD[1:0] Ramp Index Command
These bits can be used to force cycle A (Ramp A) and cycle B (Ramp B) changes in all RAMP2x operations. On timer/counter update condition, the command is executed, the IDX flag in STATUS register is updated and the IDXCMD command is cleared.
Writing zero to these bits has no effect.
Writing a '1' to any of these bits will clear the pending command.
| Value | Name | Description |
|---|---|---|
| 0 | DISABLE | Command disabled: Index toggles between cycles A and B |
| 1 | SET | Set index: cycle B will be forced in the next cycle |
| 2 | CLEAR | Clear index: cycle A will be forced in the next cycle |
| 3 | HOLD | Hold index: the next cycle will be the same as the current cycle |
Bit 2 – ONESHOT One-Shot
This bit controls one-shot operation of the TCC. When one-shot operation is enabled, the TCC will stop counting on the next overflow/underflow condition or on a stop command.
Writing a '0' to this bit has no effect
Writing a '1' to this bit will disable the one-shot operation.
Reading this bit gives the following status:
| Value | Description |
|---|---|
| 0 | The TCC will update the counter value on overflow/underflow condition and continue operation. |
| 1 | The TCC will stop counting on the next underflow/overflow condition. |
Bit 1 – LUPD Lock Update
This bit controls the update operation of the TCC buffered registers.
When CTRLBCLR.LUPD (CTRLBCLR<1>) is cleared, the hardware UPDATE registers with value from their buffered registers is enabled.
This bit has no effect when input capture operation is enabled.
Writing a '0' to this bit has no effect.
Writing a '1' to this bit will enable the registers updates on hardware UPDATE condition.
Reading this bit gives the following status:
| Value | Description |
|---|---|
| 0 | The CCBUFy, PERBUF buffer register bitfields are copied into the corresponding CCy, PER registers and register bitfields on hardware update condition. |
| 1 | The CCBUFy, PERBUF buffer registers bitfields are not copied into the corresponding CCy, PER registers and register bitfields on hardware update condition. |
Bit 0 – DIR Counter Direction
This bit is used to change the direction of the counter.
Writing a '0' to this bit has no effect
Writing a '1' to this bit will clear the bit and make the counter count up. Reading this bit gives the following status:
| Value | Description |
|---|---|
| 0 | The timer/counter is counting up (incrementing). |
| 1 | The timer/counter is counting down (decrementing). |