Atmel XMEGA B, User Manual

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164 XMEGA B [DATASHEET]
8291B–AVR–01/2013
13.12 Register Description
13.12.1 CTRLA – Control register A

Bit 7:4 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to zero
when this register is written.

Bit 3:0 – CLKSEL[3:0]: Clock Select
These bits select the clock source for the timer/counter according to Table 13-3 .
CLKSEL=0001 must be set to ensure a correct output from the waveform generator when the hi-res extension is
enabled.
Table 13-3. Clock select options
13.12.2 CTRLB – Control register B

Bit 7:4 – CCxEN: Compare or Capture Enable
Setting these bits in the FRQ or PWM waveform generation mode of operation will override the port output register for the
corresponding OCn output pin. When input capture operation is selected, the CCxEN bits enable the capture operation
for the corresponding CC channel.
Bit 7 6 5 4 3 2 1 0
+0x00
– – – – CLKSEL[3:0]
Read/Write R R R R R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
CLKSEL[3:0] Group Configuration Description
0000 OFF None (i.e, timer/counter in OFF state)
0001 DIV1 Prescaler: Clk
0010 DIV2 Prescaler: Clk/2
0011 DIV4 Prescaler: Clk/4
0100 DIV8 Prescaler: Clk/8
0101 DIV64 Prescaler: Clk/64
0110 DIV256 Prescaler: Clk/256
0111 DIV1024 Prescaler: Clk/1024
1nnn EVCHn Event channel n, n= [0,...,7]
Bit 7 6 5 4 3 2 1 0
+0x01
CCDEN CCCEN CCBEN CCAEN – WGMODE[2:0]
Read/Write R/W R/W R/W R/W R R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0