Rainbow Electronics ATmega64M1 - Manual (Page 129)

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8209A–AVR–08/09
ATmega16M1/32M1/64M1
16.11.7 ICR1H and ICR1L – Input Capture Register 1
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 105.
16.11.8 TIMSK1 – Timer/Counter1 Interrupt Mask Register
• Bit 7, 6 – Res: Reserved
These bits are reserved 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
“Interrupt Vectors in ATmega16M1/32M1/64M1” on page 54 ) is executed when the
ICF1 Flag, located in TIFR1, is set.
• Bit 4, 3 – Res: Reserved
These bits are reserved 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
“Interrupt Vectors in ATmega16M1/32M1/64M1” on page 54 ) 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
“Interrupt Vectors in ATmega16M1/32M1/64M1” on page 54 ) 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 globally
enabled), the Timer/Counter1 Overflow interrupt is enabled. The corresponding Interrupt Vector
(see
“Interrupt Vectors in ATmega16M1/32M1/64M1” on page 54 ) is executed when the TOV1
Flag, located in TIFR1, is set.
Bit 7 6 5 4 3 2 1 0
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 7 6 5 4 3 2 1 0
– – 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