Datasheet
137
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
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 113.
14.10.15 Input Capture Register 1 – ICR1H and ICR1L
14.10.16 Input Capture Register 3 – ICR3H and ICR3L
The 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 113.
14.10.17Timer/Counter1 Interrupt Mask Register – TIMSK1
14.10.18Timer/Counter3 Interrupt Mask Register – TIMSK3
• Bit 5 – ICIEn: Timer/Countern, Input Capture Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally enabled), the
Timer/Countern Input Capture interrupt is enabled. The corresponding Interrupt Vector (See “Interrupts” on
page 63.) is executed when the ICFn Flag, located in TIFRn, is set.
Bit 76543210
ICR1[15:8] ICR1H
ICR1[7:0] ICR1L
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 76543210
ICR3[15:8] ICR3H
ICR3[7:0] ICR3L
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 76543210
– –ICIE1– OCIE1C OCIE1B OCIE1A TOIE1 TIMSK1
Read/Write R R R/W R R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Bit 7654321 0
– –ICIE3– OCIE3C OCIE3B OCIE3A TOIE3 TIMSK3
Read/Write R R R/W R R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0