ATmega8U2/16U2/32U2
16.11.5 OCR1AH and OCR1AL – Output Compare Register 1 A
Bit
7
6
5
4
3
2
1
0
(0x89)
OCR1A[15:8]
OCR1A[7:0]
OCR1AH
OCR1AL
(0x88)
Read/Write
Initial Value
R/W
0
R/W
0
R/W
0
R/W
R/W
R/W
0
R/W
0
R/W
0
0
0
16.11.6 OCR1BH and OCR1BL – Output Compare Register 1 B
Bit
7
6
5
4
3
2
1
0
(0x8B)
OCR1B[15:8]
OCR1B[7:0]
OCR1BH
OCR1BL
(0x8A)
Read/Write
Initial Value
R/W
0
R/W
0
R/W
0
R/W
R/W
R/W
0
R/W
0
R/W
0
0
0
16.11.7 OCR1CH and OCR1CL – Output Compare Register 1 C
Bit
7
6
5
4
3
2
1
0
(0x8D)
OCR1C[15:8]
OCR1C[7:0]
OCR1CH
OCR1CL
(0x8C)
Read/Write
Initial Value
R/W
0
R/W
0
R/W
0
R/W
R/W
R/W
0
R/W
0
R/W
0
0
0
The Output Compare Registers contain a 16-bit value that is continuously compared with the
counter value (TCNTn). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OCnx pin.
The Output Compare Registers are 16-bit in size. To ensure that both the high and low bytes are
written simultaneously when the CPU writes to these registers, the access is performed using an
8-bit temporary High Byte Register (TEMP). This temporary register is shared by all the other
16-bit registers. See “Accessing 16-bit Registers” on page 110.
16.11.8 ICR1H and ICR1L – Input Capture Register 1
Bit
7
6
5
4
3
2
1
0
(0x87)
ICR1[15:8]
ICR1[7:0]
ICR1H
ICR1L
(0x86)
Read/Write
Initial Value
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
IThe Input Capture is updated with the counter (TCNTn) value each time an event occurs on the
ICPn pin (or optionally on the Analog Comparator output for Timer/Counter1). The Input Capture
can be used for defining the counter TOP value.
The Input Capture Register is 16-bit in size. To ensure that both the high and low bytes are read
simultaneously when the CPU accesses these registers, the access is performed using an 8-bit
temporary High Byte Register (TEMP). This temporary register is shared by all the other 16-bit
registers. See “Accessing 16-bit Registers” on page 110.
16.11.9 TIMSK1 – Timer/Counter1 Interrupt Mask Register
Bit
(0x6F)
7
6
5
4
–
3
OCIE1C
R/W
0
2
OCIE1B
R/W
0
1
OCIE1A
R/W
0
0
TOIE1
R/W
0
–
–
ICIE1
TIMSK1
Read/Write
Initial Value
R
0
R
0
R/W
0
R
0
135
7799D–AVR–11/10
ATMEL [ ATMEL ]
