ATMEGA48-20PU Atmel, ATMEGA48-20PU Datasheet - Page 212
ATMEGA48-20PU
Manufacturer Part Number
ATMEGA48-20PU
Description
IC AVR MCU 4K 20MHZ 5V 28DIP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets
1.ATAVRTS2080B.pdf
(378 pages)
2.ATMEGA48-20AU.pdf
(35 pages)
3.ATMEGA48-20PU.pdf
(377 pages)
Specifications of ATMEGA48-20PU
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
4KB (2K x 16)
Program Memory Type
FLASH
Eeprom Size
256 x 8
Ram Size
512 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)
Processor Series
ATMEGA48x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
512 B
Interface Type
2-Wire/SPI/USART/Serial
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
Minimum Operating Temperature
- 40 C
On-chip Adc
6-ch x 10-bit
Cpu Family
ATmega
Device Core
AVR
Device Core Size
8b
Frequency (max)
20MHz
Total Internal Ram Size
512Byte
# 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
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Through Hole
Pin Count
28
Package Type
PDIP
For Use With
ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 212 of 378
- Download datasheet (8Mb)
Figure 21-6. Typical Data Transmission
21.4
212
SDA
SCL
START
Multi-master Bus Systems, Arbitration and Synchronization
ATmega48/88/168
Addr MSB
1
2
The TWI protocol allows bus systems with several masters. Special concerns have been taken
in order to ensure that transmissions will proceed as normal, even if two or more masters initiate
a transmission at the same time. Two problems arise in multi-master systems:
• An algorithm must be implemented allowing only one of the masters to complete the
• Different masters may use different SCL frequencies. A scheme must be devised to
The wired-ANDing of the bus lines is used to solve both these problems. The serial clocks from
all masters will be wired-ANDed, yielding a combined clock with a high period equal to the one
from the Master with the shortest high period. The low period of the combined clock is equal to
the low period of the Master with the longest low period. Note that all masters listen to the SCL
line, effectively starting to count their SCL high and low time-out periods when the combined
SCL line goes high or low, respectively.
transmission. All other masters should cease transmission when they discover that they have
lost the selection process. This selection process is called arbitration. When a contending
master discovers that it has lost the arbitration process, it should immediately switch to Slave
mode to check whether it is being addressed by the winning master. The fact that multiple
masters have started transmission at the same time should not be detectable to the slaves,
that is, the data being transferred on the bus must not be corrupted.
synchronize the serial clocks from all masters, in order to let the transmission proceed in a
lockstep fashion. This will facilitate the arbitration process.
SLA+R/W
Addr LSB
7
R/W
8
ACK
9
Data MSB
1
2
Data Byte
7
Data LSB
8
ACK
9
2545S–AVR–07/10
STOP
Related parts for ATMEGA48-20PU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 20MHZ 5V 32TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 20MHZ 5V 32-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 4K FLASH 20MHZ 28QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 4KB FLASH 20MHZ 32QFN
Manufacturer:
Atmel
Datasheet: