19.11.5 Input Capture Register 1 Low and High byte

The ICR1L and ICR1H register pair represents the 16-bit value, ICR1. The low byte [7:0] (suffix L) is accessible at the original offset. The high byte [15:8] (suffix H) can be accessed at offset + 0x01. For more details on reading and writing 16-bit registers, refer to Accessing 16-bit Timer/Counter Registers.

Name: ICR1L and ICR1H
Offset: 0x86
Reset: 0x00
Property: -

Bit 15141312111098 
 ICR1[15:8] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 
Bit 76543210 
 ICR1[7:0] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 

Bits 15:0 – ICR1[15:0] Input Capture 1

The input capture is updated with the counter (TCNT1) value each time an event occurs on the ICP1 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. Refer to Accessing 16-bit Timer/Counter Registers for details.