AT83C26-RKRUL Atmel, AT83C26-RKRUL Datasheet - Page 10

• Manufacturer Part Number: AT83C26-RKRUL
• Description: RFID Modules & Development Tools 3V Smart card reader
• Manufacturer: Atmel

Operational Modes
TWI Bus Control
TWI Commands
Frame Structure
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AT83C26
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.
The TWI-bus interface can be used:
The structure of the TWI bus data frames is made of one or a series of write and read com-
mands completed by STOP.
Write commands to the AT83C26 have the structure:
Read commands to the AT83C26 have the structure:
The ADDRESS BYTE is sampled on A2/CK and A1/RST after each reset (hard/soft/general
call) but A2/CK, A1/RST can be used for transparent mode after the reset.
–
–
–
–
–
–
–
–
–
–
–
–
–
–
ADDRESS BYTE + COMMAND BYTE + DATA BYTE(S)
ADDRESS BYTE + DATA BYTE(S)
To configure the AT83C26
To select interface
To select the operating mode of the card: 1.8V, 3V or 5V
To configure the automatic activation sequence
To start or stop sessions (activation and de-activation sequences)
To initiate a warm reset
To control the clock to the card in active mode
To control the clock to the card in stand-by mode (stop LOW, stop HIGH or running)
To enter or leave the card stand-by or power-down modes
To select the interface (connection to the host I/O/C4/C8)
To request the status (card present or not, over-current and out of range supply
voltage occurrence)
To drive and monitor the card contacts by software
To accurately measure the ATR delay when automatic activation is used
Re-use the AT83C24 command set for the first DC/DC and smart card interface with
the following changes:
•CKS extended to CONFIG2[0:3], CKS=8 selects CLK/3 and CKS>8 is reserved
•The slave address byte for TWI write commands is 0100 A
for TWI read commands
2
A
1
10 and 0100 A
7511D–SCR–02/07
2
A
1
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