AT91SAM7S256D-AU Atmel, AT91SAM7S256D-AU Datasheet - Page 295

• 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

29. Two-wire Interface (TWI) SAM7S512/256/128/64/321/32
29.1
29.2
Overview
List of Abbreviations
NOTE: This definition of the TWI does not pertain to SAM7S16/161. For SAM7S16/161, see
Section 30.
The 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-ori-
ented 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 programmable as master transmitter or
master receiver with sequential or single-byte access. A configurable baud rate generator per-
mits the output data rate to be adapted to a wide range of core clock frequencies. Below,
29-1
Table 29-1.
Notes:
Table 29-2.
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
N
P
S
Sr
DADR
IADR
R
W
lists the compatibility level of the Atmel Two-wire Interface and a full I2C compatible device.
1. START + b000000001 + Ack + Sr
2. A repeated start condition is only supported in Master Receiver mode. See
“Internal Address” on page 301
(1)
Atmel TWI compatibility with i2C Standard
Abbreviations
Description
Two-wire Interface
Acknowledge
Not Acknowledge
Stop
Start
Repeated Start
Device Address
Internal Address
Read
Write
Atmel TWI
Supported
Supported
Supported
Not Supported
Not Fully Supported
Supported
Not Supported
Supported
SAM7S Series [DATASHEET]
(2)
6175M–ATARM–26-Oct-12
Section 29.6.5
Table
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