Datasheet
ATmega164A/PA/324A/PA/644A/PA/1284/P
2018 Microchip Technology Inc. Data Sheet Complete DS40002070A-page 141
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 117.
16.12.8 OCR3AH and OCR3AL – Output Compare Register3 A
16.12.9 OCR3BH and OCR3BL – Output Compare Register3 B
The Output Compare Registers contain a 16-bit value that is continuously compared with the counter value
(TCNT3). 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 117.
16.12.10ICR1H and ICR1L – Input Capture Register 1
The Input Capture is updated with the counter (TCNT1) 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 117.
16.12.11ICR3H and ICR3L – Input Capture Register 3
Bit 76543210
(0x99) OCR3A[15:8] OCR3AH
(0x98) OCR3A[7:0] OCR3AL
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
(0x9B) OCR3B[15:8] OCR3BH
(0x9A) OCR3B[7:0] OCR3BL
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
(0x87) ICR1[15:8] ICR1H
(0x86) ICR1[7:0] ICR1L
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
(0x97) ICR3[15:8] ICR3H
(0x96) ICR3[7:0] ICR3L
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000