117
8155C–AVR–02/11
ATmega32A
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. See “Accessing 16-bit Registers” on page 94.
16.10.7
TIMSK – Timer/Counter Interrupt Mask Register
(1)
Note:
1. This register contains interrupt control bits for several Timer/Counters, but only Timer1 bits are
described in this section. The remaining bits are described in their respective timer sections.
Bit 5 – TICIE1: 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 45.) is executed when the ICF1 Flag, located in TIFR, is set.
Bit 4 – 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 45.) is executed when the OCF1A Flag, located in
TIFR, is set.
Bit 3 – 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 45.) is executed when the OCF1B Flag, located in
TIFR, is set.
Bit 2 – TOIE1: Timer/Counter1, Overflow 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 Overflow Interrupt is enabled. The corresponding Interrupt Vector
(See “Interrupts” on page 45.) is executed when the TOV1 Flag, located in TIFR, is set.
16.10.8
TIFR – Timer/Counter Interrupt Flag Register
Note:
1. This register contains flag bits for several Timer/Counters, but only Timer1 bits are described
in this section. The remaining bits are described in their respective timer sections.
Bit
7
6
5
4
3
2
1
0
OCIE2
TOIE2
TICIE1
OCIE1A
OCIE1B
TOIE1
OCIE0
TOIE0
TIMSK
Read/Write
R/W
Initial Value
0
Bit
765
4321
0
OCF2
TOV2
ICF1
OCF1A
OCF1B
TOV1
OCF0
TOV0
TIFR
Read/Write
R/W
Initial Value
000
0000
0