Datasheet

139
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
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.
16.12.11 ICR3H and ICR3L – Input Capture Register 3
The Input Capture is updated with the counter (TCNT3) value each time an event occurs on the
ICPn pin (or optionally on the Analog Comparator output for Timer/Counter3). 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.
16.12.12 TIMSK1 – Timer/Counter1 Interrupt Mask Register
• Bit 7:6 – Reserved
These bits are unused and will always read as zero.
• Bit 5 – ICIE1: Timer/Counter1, 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/Counter1 Input Capture interrupt is enabled. The corresponding Interrupt
Vector (see “Interrupts” on page 61) is executed when the ICF1 Flag, located in TIFR1, is set.
• Bit 4:3 – Reserved
These bits are unused and will always read as zero.
• Bit 2 – OCIE1B: Timer/Counter1, Output Compare B Match Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally
enabled), the Timer/Counter1 Output Compare B Match interrupt is enabled. The corresponding
Interrupt Vector (see “Interrupts” on page 61) is executed when the OCF1B Flag, located in
TIFR1, is set.
• Bit 1 – OCIE1A: Timer/Counter1, Output Compare A Match Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts globally
enabled), the Timer/Counter1 Output Compare A Match interrupt is enabled. The corresponding
Interrupt Vector (see “Interrupts” on page 61) is executed when the OCF1A Flag, located in
TIFR1, is set.
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
Bit 76543210
(0x6F)
– –ICIE1– – OCIE1B OCIE1A TOIE1 TIMSK1
Read/Write R R R/W R R R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0