ATMEGA48-20AU Atmel, ATMEGA48-20AU Datasheet - Page 227

• Manufacturer Part Number: ATMEGA48-20AU
• Description: IC AVR MCU 4K 20MHZ 5V 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48-20AU

• 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 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• 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: 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: 8-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: Surface Mount
• Pin Count: 32
• Package Type: TQFP
• For Use With: ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRDRAGON - 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

21.7.3
2545S–AVR–07/10
Slave Receiver Mode
Figure 21-14. Formats and States in the Master Receiver Mode
In the Slave Receiver mode, a number of data bytes are received from a Master Transmitter
(see
are zero or are masked to zero.
Figure 21-15. Data transfer in Slave Receiver mode
To initiate the Slave Receiver mode, TWAR and TWCR must be initialized as follows:
TWAR
value
Figure
Successfull
reception
from a slave
receiver
Next transfer
started with a
repeated start
condition
Not acknowledge
received after the
slave address
Arbitration lost in slave
address or data byte
Arbitration lost and
addressed as slave
SDA
SCL
21-15). All the status codes mentioned in this section assume that the prescaler bits
From master to slave
From slave to master
$08
S
TWA6
SLA
Device 1
RECEIVER
SLAVE
TWA5
R
MR
TRANSMITTER
Device 2
A or A
DATA
MASTER
$40
$48
$38
$68
A
A
A
$78
TWA4
Other master
Other master
n
continues
continues
Device’s Own Slave Address
P
$B0
Device 3
DATA
A
TWA3
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the 2-Wire Serial Bus. The
prescaler bits are zero or masked to zero
........
$50
$38
To corresponding
states in slave mode
A
A
TWA2
Other master
Device n
DATA
continues
ATmega48/88/168
V
CC
$58
A
TWA1
R1
$10
P
R
S
R2
SLA
TWA0
W
R
TWGCE
MT
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