AT83C24NDS-PRRUM ATMEL [ATMEL Corporation], AT83C24NDS-PRRUM Datasheet - Page 7

• Manufacturer Part Number: AT83C24NDS-PRRUM
• Description: Smart Card Reader Interface with Power Management
• Manufacturer: ATMEL [ATMEL Corporation]

Address Byte
4234F–SCR–10/05
The first byte to send to the device is the address byte. The device controls if the hardware
address (A2/CK, A1/RST, A0/3V pins on reset) corresponds to the address given in the
address byte (A2, A1, A0 bits).
If the level is not stable on A2/CK pin (or A1/RST pin, or A0/3V pin) at reset, the user has to send
the commands to the possible address taken by the device.
If A2/CK to A0/3V are tied to the host microcontroller and their reset values are unknown, a gen-
eral call on the TWI bus allows to reset all the AT83C24 devices and set their address after
A2/CK to A0/3V are fixed.
Up to 8 devices can be connected on the same TWI bus. Each device is configured with a differ-
ent combination on A2/CK, A1/RST, A0/3V pins. The corresponding address byte values for
read/write operations are listed below.
Table 2. Address Byte Values
Figure 2. Address Byte
(A2/CK pin)
A2
0
0
0
0
1
1
1
1
(A1/RST pin)
b7
0
Slave Address on 7 Bits
A1
0
0
1
1
0
0
1
1
b6
1
b5
0
b4
0
(A0/3V pin)
A0
b3
A2
0
1
0
1
0
1
0
1
b2
A1
1 for READ Command
0 for WRITE Command
b1
A0
Address Byte
Command
Read
0x4D
0x41
0x43
0x45
0x47
0x49
0x4B
0x4F
R/W
b0
for
Address Byte
Command
Write
0x4C
0x4A
0x4E
0x40
0x42
0x44
0x46
0x48
for
AT83C24
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