35.8.2. Control B Clear
This register allows the user to clear bits in the CTRLB register without doing a read-modify-write
operation. Changes in this register will also be reflected in the Control B Set register (CTRLBSET).
Name:
CTRLBCLR
Offset:
0x04
Reset:
0x00
Property:
PAC Write-Protection, Read-Synchronized, Write-Synchronized
Bit
7
6
5
4
3
2
1
0
CMD[2:0]
ONESHOT
LUPD
DIR
Access
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
Bits 7:5 – CMD[2:0]: Command
These bits are used for software control of the TC. The commands are executed on the next prescaled
GCLK_TC clock cycle. When a command has been executed, the CMD bit group will be read back as
zero.
Writing 0x0 to these bits has no effect.
Writing a '1' to any of these bits will clear the pending command.
Bit 2 – ONESHOT: One-Shot on Counter
This bit controls one-shot operation of the TC.
Writing a '0' to this bit has no effect
Writing a '1' to this bit will disable one-shot operation.
Value
Description
0
The TC will wrap around and continue counting on an overflow/underflow condition.
1
The TC will wrap around and stop on the next underflow/overflow condition.
Bit 1 – LUPD: Lock Update
This bit controls the update operation of the TC buffered registers.
When CTRLB.LUPD is set, no any update of the registers with value of its buffered register is performed
on hardware UPDATE condition. Locking the update ensures that all buffer registers are valid before an
hardware update is performed. After all the buffer registers are loaded correctly, the buffered registers can
be unlocked.
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 clear the LUPD bit.
Value
Description
0
The CCBUFx and PERBUF buffer registers value are copied into CCx and PER registers on
hardware update condition.
1
The CCBUFx and PERBUF buffer registers value are not copied into CCx and PER registers
on hardware update condition.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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