ATMEGA128A-AU Atmel, ATMEGA128A-AU Datasheet - Page 109
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ATMEGA128A-AU
Manufacturer Part Number
ATMEGA128A-AU
Description
MCU 8BIT 128K ISP FLASH 64-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA128A-AU
Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
EBI/EMI, I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
53
Program Memory Size
128KB (64K x 16)
Program Memory Type
FLASH
Eeprom Size
4K x 8
Ram Size
4K 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
64-TQFP, 64-VQFP
Processor Series
ATMEGA128x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
4 KB
Interface Type
JTAG
Maximum Clock Frequency
16 MHz
Number Of Programmable I/os
53
Number Of Timers
4
Operating Supply Voltage
2.7 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 8 Channel
On-chip Dac
10 bit, 8 Channel
Cpu Family
ATmega
Device Core
AVR
Device Core Size
8b
Frequency (max)
16MHz
Total Internal Ram Size
4KB
# I/os (max)
53
Number Of Timers - General Purpose
4
Operating Supply Voltage (typ)
3.3/5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
2.7V
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Surface Mount
Pin Count
64
Package Type
TQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
Q4784435
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA128A-AU
Manufacturer:
ATMEL
Quantity:
9 000
Company:
Part Number:
ATMEGA128A-AU
Manufacturer:
ATMEL
Quantity:
3 480
Part Number:
ATMEGA128A-AU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Company:
Part Number:
ATMEGA128A-AUR
Manufacturer:
ATMEL
Quantity:
3 000
Part Number:
ATMEGA128A-AUR
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
14.11.2
14.11.3
14.11.4
8151H–AVR–02/11
TCNT0 - Timer/Counter Register
OCR0 - Output Compare Register
ASSR - Asynchronous Status Register
Table 14-6.
The Timer/Counter Register gives direct access, both for read and write operations, to the
Timer/Counter unit 8-bit counter. Writing to the TCNT0 Register blocks (removes) the compare
match on the following timer clock. Modifying the counter (TCNT0) while the counter is running,
introduces a risk of missing a compare match between TCNT0 and the OCR0 Register.
The Output Compare Register contains an 8-bit value that is continuously compared with the
counter value (TCNT0). A match can be used to generate an output compare interrupt, or to
generate a waveform output on the OC0 pin.
• Bit 3 – AS0: Asynchronous Timer/Counter0
When AS0 is written to zero, Timer/Counter0 is clocked from the I/O clock, clk
written to one, Timer/Counter is clocked from a crystal Oscillator connected to the Timer Oscilla-
tor 1 (TOSC1) pin. When the value of AS0 is changed, the contents of TCNT0, OCR0, and
TCCR0 might be corrupted.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
CS02
0
0
0
0
1
1
1
1
Clock Select Bit Description
R
R/W
R/W
7
–
0
CS01
7
0
7
0
0
0
1
1
0
0
1
1
R
6
–
0
R/W
R/W
6
0
6
0
CS00
0
1
0
1
0
1
0
1
R
5
–
0
R/W
R/W
5
0
5
0
Description
No clock source (Timer/Counter stopped)
clk
clk
clk
clk
clk
clk
clk
R
4
–
0
T
T
T0S
T0S
T0S
T0S
T0S
R/W
R/W
0
0
S
S
4
0
4
0
/256 (From prescaler)
/1024 (From prescaler)
TCNT0[7:0]
OCR0[7:0]
/(No prescaling)
/8 (From prescaler)
/32 (From prescaler)
/64 (From prescaler)
/128 (From prescaler)
AS0
R/W
3
0
R/W
R/W
3
0
3
0
TCN0UB
R
2
0
R/W
R/W
2
0
2
0
OCR0UB
R
1
0
ATmega128A
R/W
R/W
1
0
1
0
TCR0UB
I/O
R
R/W
R/W
0
0
0
0
0
0
. When AS0 is
TCNT0
ASSR
OCR0
109