ATMEGA88-20PU Atmel, ATMEGA88-20PU Datasheet - Page 257

• Manufacturer Part Number: ATMEGA88-20PU
• Description: IC AVR MCU 8K 20MHZ 5V 28DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA88-20PU

• 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 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• 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: 6-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 28
• Package Type: PDIP
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRTS2080A, ATASTK512-EK1-IND
• Minimum Operating Temperature: - 40 C
• Package: 28PDIP
• Family Name: ATmega
• Maximum Speed: 20 MHz
• For Use With: ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.8.3
23.8.3.1
23.8.3.2
23.8.4
2545S–AVR–07/10
ADCL and ADCH – The ADC Data Register
ADCSRB – ADC Control and Status Register B
ADLAR = 0
ADLAR = 1
When an ADC conversion is complete, the result is found in these two registers.
When ADCL is read, the ADC Data Register is not updated until ADCH is read. Consequently, if
the result is left adjusted and no more than 8-bit precision is required, it is sufficient to read
ADCH. Otherwise, ADCL must be read first, then ADCH.
The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the way the result is read from
the registers. If ADLAR is set, the result is left adjusted. If ADLAR is cleared (default), the result
is right adjusted.
• ADC9:0: ADC Conversion Result
These bits represent the result from the conversion, as detailed in
page
• Bit 7, 5:3 – Res: Reserved Bits
These bits are reserved for future use. To ensure compatibility with future devices, these bist
must be written to zero when ADCSRB is written.
• Bit 2:0 – ADTS2:0: ADC Auto Trigger Source
If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger
an ADC conversion. If ADATE is cleared, the ADTS2:0 settings will have no effect. A conversion
will be triggered by the rising edge of the selected Interrupt Flag. Note that switching from a trig-
ger source that is cleared to a trigger source that is set, will generate a positive edge on the
Bit
(0x79)
(0x78)
Read/Write
Initial Value
Bit
(0x79)
(0x78)
Read/Write
Initial Value
Bit
(0x7B)
Read/Write
Initial Value
254.
ADC7
ADC9
ADC1
15
15
R
R
R
R
7
0
0
–
7
0
0
R
7
–
0
ADC6
ADC8
ADC0
ACME
R/W
14
14
R
R
R
R
6
0
0
–
6
0
0
6
0
ADC5
ADC7
13
13
R
R
R
R
–
5
0
0
–
5
0
0
R
5
–
0
ADC4
ADC6
12
12
R
R
R
R
–
4
0
0
–
4
0
0
R
4
–
0
ADC3
ADC5
11
11
R
R
R
R
–
3
0
0
–
3
0
0
R
3
–
0
ADTS2
ADC4
ADC2
R/W
ATmega48/88/168
10
10
R
R
–
2
R
R
0
0
–
2
0
0
2
0
“ADC Conversion Result” on
ADTS1
ADC3
ADC9
ADC1
R/W
R
R
R
R
9
–
1
0
0
9
1
0
0
1
0
ADTS0
ADC2
ADC8
ADC0
R/W
R
R
R
R
8
–
0
0
0
8
0
0
0
0
0
ADCSRB
ADCH
ADCL
ADCH
ADCL
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