AT91SAM7S256D-AU Atmel, AT91SAM7S256D-AU Datasheet - Page 319

• Manufacturer Part Number: AT91SAM7S256D-AU
• Description: ARM Microcontrollers - MCU 256K Flash SRAM 64K ARM based MCU
• Manufacturer: Atmel
• Series: SAM7S256r

Specifications of AT91SAM7S256D-AU

• Rohs: yes
• Core: ARM
• Processor Series: AT91SAM
• Data Bus Width: 16 bit/32 bit
• Maximum Clock Frequency: 55 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 64 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 3 V to 3.6 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-64
• Mounting Style: SMD/SMT
• Interface Type: 2-Wire, I2S, SPI, USART
• Length: 7 mm

30. Two Wire Interface (TWI) SAM7S161/16
30.1
30.2
N O T E : T h i s d e f i n i t i o n o f t h e T W I d o e s n o t p e r t a i n t o S A M 7 S 5 1 2 / 2 5 6 / 1 2 8 / 6 5 / 3 2 / 3 2 1 . F o r
SAM7S512/256/128/65/32/321, see Section 29.
Overview
The Atmel Two-wire Interface (TWI) interconnects components on a unique two-wire bus, made up of one clock
line and one data line with speeds of up to 400 Kbits per second, based on a byte-oriented transfer format. It can
be used with any Atmel Two-wire Interface bus Serial EEPROM and I²C compatible device such as Real Time
Clock (RTC), Dot Matrix/Graphic LCD Controllers and Temperature Sensor, to name but a few. The TWI is pro-
grammable as a master or a slave with sequential or single-byte access. Multiple master capability is supported.
Arbitration of the bus is performed internally and puts the TWI in slave mode automatically if the bus arbitration is
lost.
A configurable baud rate generator permits the output data rate to be adapted to a wide range of core clock
frequencies.
Below,
ible device.
Table 30-1.
Note:
List of Abbreviations
Table 30-2.
I2C Standard
Standard Mode Speed (100 KHz)
Fast Mode Speed (400 KHz)
7 or 10 bits Slave Addressing
START BYTE
Repeated Start (Sr) Condition
ACK and NACK Management
Slope control and input filtering (Fast mode)
Clock stretching
Abbreviation
TWI
A
NA
P
S
Sr
SADR
ADR
R
W
Table 30-1
1. START + b000000001 + Ack + Sr
(1)
Atmel TWI compatibility with i2C Standard
Abbreviations
lists the compatibility level of the Atmel Two-wire Interface in Master Mode and a full I2C compat-
Description
Two-wire Interface
Acknowledge
Non Acknowledge
Stop
Start
Repeated Start
Slave Address
Any address except SADR
Read
Write
Atmel TWI
Supported
Supported
Supported
Not Supported
Supported
Supported
Not Supported
Supported
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
319