190
8331B–AVR–03/12
Atmel AVR XMEGA AU
14.12.15 PERH – Period register H
• Bit 7:0 – PER[15:8]
These bits hold the MSB of the 16-bit period register.
14.12.16 CCxL – Compare or Capture x register L
The CCxH and CCxL register pair represents the 16-bit value, CCx. These 16-bit register pairs
have two functions, depending of the mode of operation.
For capture operation, these registers constitute the second buffer level and access point for the
CPU and DMA.
For compare operation, these registers are continuously compared to the counter value. Nor-
mally, the outputs form the comparators are then used for generating waveforms.
CCx registers are updated with the buffer value from their corresponding CCxBUF register when
an UPDATE condition occurs.
• Bit 7:0 – CCx[7:0]
These bits hold the LSB of the 16-bit compare or capture register.
14.12.17 CCxH – Compare or Capture x register H
• Bit 7:0 – CCx[15:8]
These bits hold the MSB of the 16-bit compare or capture register.
14.12.18 PERBUFL – Timer/Counter Period Buffer L
The PERBUFH and PERBUFL register pair represents the 16-bit value, PERBUF. This 16-bit
register serves as the buffer for the period register (PER). Accessing this register using the CPU
or DMA will affect the PERBUFV flag.
Bit
7
6
5
4
3
2
1
0
PER[15:8]
PERH
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
1
1
1
1
1
1
1
1
Bit
7
6
5
4
3
2
1
0
CCx[7:0]
CCxL
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
CCx[15:8]
CCxH
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
PERBUF[7:0]
PERBUFL
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
1
1
1
1
1
1
1
1
