ATMEGA48-20PU Atmel, ATMEGA48-20PU Datasheet - Page 235
![IC AVR MCU 4K 20MHZ 5V 28DIP](/photos/7/21/72189/453-28-dip_sml.jpg)
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: 235 of 378
- Download datasheet (8Mb)
21.9
21.9.1
21.9.2
2545S–AVR–07/10
Register Description
TWBR – TWI Bit Rate Register
TWCR – TWI Control Register
• Two or more masters are accessing different slaves. In this case, arbitration will occur in the
This is summarized in
Figure 21-21. Possible Status Codes Caused by Arbitration
• Bits 7..0 – TWI Bit Rate Register
TWBR selects the division factor for the bit rate generator. The bit rate generator is a frequency
divider which generates the SCL clock frequency in the Master modes. See
Unit” on page 215
The TWCR is used to control the operation of the TWI. It is used to enable the TWI, to initiate a
Master access by applying a START condition to the bus, to generate a Receiver acknowledge,
to generate a stop condition, and to control halting of the bus while the data to be written to the
bus are written to the TWDR. It also indicates a write collision if data is attempted written to
TWDR while the register is inaccessible.
Bit
(0xB8)
Read/Write
Initial Value
Bit
(0xBC)
Read/Write
Initial Value
SLA bits. Masters trying to output a one on SDA while another Master outputs a zero will lose
the arbitration. Masters losing arbitration in SLA will switch to Slave mode to check if they are
being addressed by the winning Master. If addressed, they will switch to SR or ST mode,
depending on the value of the READ/WRITE bit. If they are not being addressed, they will
switch to not addressed Slave mode or wait until the bus is free and transmit a new START
condition, depending on application software action.
START
TWBR7
TWINT
R/W
R/W
7
0
7
0
for calculating bit rates.
Address / General Call
Figure
Direction
received
Own
TWBR6
TWEA
R/W
R/W
Yes
Arbitration lost in SLA
6
0
6
0
SLA
21-21. Possible status values are given in circles.
Write
Read
TWBR5
TWSTA
R/W
R/W
No
5
0
5
0
TWSTO
TWBR4
R/W
R/W
4
0
4
0
68/78
38
B0
Arbitration lost in Data
TWBR3
TWWC
TWI bus will be released and not addressed slave mode will be entered
A START condition will be transmitted when the bus becomes free
Data byte will be received and NOT ACK will be returned
Data byte will be received and ACK will be returned
Last data byte will be transmitted and NOT ACK should be received
Data byte will be transmitted and ACK should be received
R/W
R
3
0
3
0
Data
TWBR2
TWEN
R/W
R/W
ATmega48/88/168
2
0
2
0
TWBR1
R/W
R
1
0
1
–
0
“Bit Rate Generator
TWBR0
TWIE
R/W
R/W
0
0
0
0
STOP
TWBR
TWCR
235
Related parts for ATMEGA48-20PU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![ATMEGA48-20AI](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
![ATmega48](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATmega48 Automotive](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
![ATMEGA48-20AU](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 20MHZ 5V 32TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20MU](/photos/12/32/123213/atmega48-20mu_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 20MHZ 5V 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20AJ](/photos/6/91/69154/313-32-tqfp_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-TQFP
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20MI](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20MJ](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 32-QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20PI](/photos/7/21/72189/453-28-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20PJ](/photos/7/21/72189/453-28-dip_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K 5V 20MHZ 28-DIP
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20MMU](/photos/12/13/121311/atmega48-20mmu_tmb.jpg)
Part Number:
Description:
IC AVR MCU 4K FLASH 20MHZ 28QFN
Manufacturer:
Atmel
Datasheet:
![ATMEGA48-20MUR](/images/manufacturer_photos/0/0/78/atmel_tmb.jpg)
Part Number:
Description:
MCU AVR 4KB FLASH 20MHZ 32QFN
Manufacturer:
Atmel
Datasheet: