ATMEGA88-20AJ Atmel, ATMEGA88-20AJ Datasheet - Page 134

• Manufacturer Part Number: ATMEGA88-20AJ
• Description: IC MCU AVR 8K 5V 20MHZ 32-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88-20AJ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA88-24AJ; ATMEGA88-24AJ

15.11.7
15.11.8
134
ATmega48/88/168
ICR1H and ICR1L – Input Capture Register 1
TIMSK1 – Timer/Counter1 Interrupt Mask Register
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.
• Bit 7, 6 – Res: Reserved Bits
These bits are unused bits in the ATmega48/88/168, 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 55) is executed when the ICF1 Flag, located in TIFR1, is set.
• Bit 4, 3 – Res: Reserved Bits
These bits are unused bits in the ATmega48/88/168, 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 55) 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 55) 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
Bit
(0x87)
(0x86)
Read/Write
Initial Value
Bit
(0x6F)
Read/Write
Initial Value
“Interrupts” on page
See “Accessing 16-bit Registers” on page 109.
R/W
R
7
0
7
–
0
R/W
55) is executed when the TOV1 Flag, located in TIFR1, is set.
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
2545S–AVR–07/10
TIMSK1
ICR1H
ICR1L