ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 122

• Manufacturer Part Number: ATMEGA169
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Input Capture Register 1 –
ICR1H and ICR1L
Timer/Counter1 Interrupt
Mask Register – TIMSK1
122
ATmega169/V
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 per-
formed 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 98.
• 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 glo-
bally enabled), the Timer/Counter1 Input Capture interrupt is enabled. The
corresponding Interrupt Vector (See “Interrupts” on page 46.) is executed when the
ICF1 Flag, located in TIFR1, is set.
• 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 glo-
bally enabled), the Timer/Counter1 Output Compare B Match interrupt is enabled. The
corresponding Interrupt Vector (See “Interrupts” on page 46.) 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 glo-
bally enabled), the Timer/Counter1 Output Compare A Match interrupt is enabled. The
corresponding Interrupt Vector (See “Interrupts” on page 46.) is executed when the
OCF1A Flag, located in TIFR1, is set.
• Bit 0 – TOIE1: Timer/Counter1, Overflow Interrupt Enable
When this bit is written to one, and the I-flag in the Status Register is set (interrupts glo-
bally enabled), the Timer/Counter1 Overflow interrupt is enabled. The corresponding
Interrupt Vector (See “Interrupts” on page 46.) is executed when the TOV1 Flag, located
in TIFR1, is set.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
R/W
R
7
0
7
–
0
R/W
R
6
0
6
–
0
ICIE1
R/W
R/W
5
0
5
0
R/W
R
4
0
4
–
0
ICR1[15:8]
ICR1[7:0]
R/W
R
3
0
3
–
0
OCIE1B
R/W
R/W
2
0
2
0
OCIE1A
R/W
R/W
1
0
1
0
TOIE1
R/W
R/W
0
0
0
0
2514P–AVR–07/06
TIMSK1
ICR1H
ICR1L