ATMEGA128A-AU Atmel, ATMEGA128A-AU Datasheet - Page 96
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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
14.5.1
14.5.2
14.5.3
8151H–AVR–02/11
Force Output Compare
Compare Match Blocking by TCNT0 Write
Using the Output Compare Unit
Figure 14-3. Output Compare Unit, Block Diagram
The OCR0 Register is double buffered when using any of the Pulse Width Modulation (PWM)
modes. For the normal and Clear Timer on Compare (CTC) modes of operation, the double buff-
ering is disabled. The double buffering synchronizes the update of the OCR0 Compare Register
to either top or bottom of the counting sequence. The synchronization prevents the occurrence
of odd-length, non-symmetrical PWM pulses, thereby making the output glitch-free.
The OCR0 Register access may seem complex, but this is not case. When the double buffering
is enabled, the CPU has access to the OCR0 buffer Register, and if double buffering is disabled
the CPU will access the OCR0 directly.
In non-PWM waveform generation modes, the match output of the comparator can be forced by
writing a one to the Force Output Compare (FOC0) bit. Forcing compare match will not set the
OCF0 flag or reload/clear the timer, but the OC0 pin will be updated as if a real compare match
had occurred (the COM01:0 bits settings define whether the OC0 pin is set, cleared or toggled).
All CPU write operations to the TCNT0 Register will block any compare match that occurs in the
next timer clock cycle, even when the timer is stopped. This feature allows OCR0 to be initialized
to the same value as TCNT0 without triggering an interrupt when the Timer/Counter clock is
enabled.
Since writing TCNT0 in any mode of operation will block all compare matches for one timer clock
cycle, there are risks involved when changing TCNT0 when using the output compare channel,
independently of whether the Timer/Counter is running or not. If the value written to TCNT0
equals the OCR0 value, the compare match will be missed, resulting in incorrect waveform gen-
top
bottom
FOCn
OCRn
Waveform Generator
WGMn1:0
=
(8-bit Comparator )
DATA BUS
COMn1:0
TCNTn
OCFn (Int.Req.)
ATmega128A
OCxy
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