ATMEGA88-20MUR Atmel, ATMEGA88-20MUR Datasheet - Page 155

• Manufacturer Part Number: ATMEGA88-20MUR
• Description: MCU AVR 8K FLASH 20MHZ 32QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88-20MUR

• 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: *
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: SPI/TWI/USART
• Total Internal Ram Size: 1KB
• # I/os (max): 23
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 32
• Package Type: MLF EP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.11.2
2545S–AVR–07/10
TCCR2B – Timer/Counter Control Register B
Table 17-8.
Notes:
• Bit 7 – FOC2A: Force Output Compare A
The FOC2A bit is only active when the WGM bits specify a non-PWM mode.
However, for ensuring compatibility with future devices, this bit must be set to zero when
TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2A bit,
an immediate Compare Match is forced on the Waveform Generation unit. The OC2A output is
changed according to its COM2A1:0 bits setting. Note that the FOC2A bit is implemented as a
strobe. Therefore it is the value present in the COM2A1:0 bits that determines the effect of the
forced compare.
A FOC2A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using
OCR2A as TOP.
The FOC2A bit is always read as zero.
• Bit 6 – FOC2B: Force Output Compare B
The FOC2B bit is only active when the WGM bits specify a non-PWM mode.
However, for ensuring compatibility with future devices, this bit must be set to zero when
TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2B bit,
an immediate Compare Match is forced on the Waveform Generation unit. The OC2B output is
changed according to its COM2B1:0 bits setting. Note that the FOC2B bit is implemented as a
strobe. Therefore it is the value present in the COM2B1:0 bits that determines the effect of the
forced compare.
Bit
(0xB1)
Read/Write
Initial Value
Mode
0
1
2
3
4
5
6
7
1. MAX= 0xFF
2. BOTTOM= 0x00
WGM2
0
0
0
0
1
1
1
1
Waveform Generation Mode Bit Description
FOC2A
W
7
0
WGM1
0
0
1
1
0
0
1
1
FOC2B
W
6
0
WGM0
0
1
0
1
0
1
0
1
R
5
–
0
Timer/Counter
Mode of
Operation
Normal
PWM, Phase
Correct
CTC
Fast PWM
Reserved
PWM, Phase
Correct
Reserved
Fast PWM
R
4
–
0
WGM22
R
3
0
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
ATmega48/88/168
CS22
–
–
R
2
0
Immediate
Immediate
Update of
BOTTOM
BOTTOM
OCRx at
CS21
R/W
1
0
TOP
TOP
–
–
CS20
R/W
0
0
Set on
TOV Flag
BOTTOM
BOTTOM
MAX
MAX
MAX
TOP
TCCR2B
–
–
(1)(2)
155