DEMOKITCRX14 STMicroelectronics, DEMOKITCRX14 Datasheet - Page 17

• Manufacturer Part Number: DEMOKITCRX14
• Description: RFID EVALUATION KIT ISO14443-B
• Manufacturer: STMicroelectronics
• Type: Development kitr

Specifications of DEMOKITCRX14

• Contents: CD-ROM, CRX14 Board, USB Transceiver, Samples and Documentation
• Processor To Be Evaluated: CRX14
• Interface Type: I2C
• Operating Supply Voltage: 5 V
• For Use With/related Products: CRX14
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-3704

APPLYING THE I²C PROTOCOL TO THE CRX14 REGISTERS
I²C Parameter Register Protocol
Figure 11.
Parameter Register. The new value becomes ac-
tive after the I²C STOP condition.
Figure 12.
ister contents. The CRX14 sends and re-sends the
Figure 11. Host-to-CRX14 Transfer: I²C Write to Parameter Register
Figure 12. CRX14-to-Host Transfer: I²C Random Address Read from Parameter Register
Figure 13. CRX14-to-Host Transfer: I²C Current Address Read from Parameter Register
CRX14 Read
Bus Master
Bus Slave
shows how to read the Parameter Reg-
CRX14 Write
shows how new data is written to the
Bus Master
Bus Slave
S
T
A
R
T
1 0 1 0 X X X
CRX14 Read
Device Select
Bus Master
Bus Slave
S
T
A
R
T
Code
1 0 1 0 X X X
Device Select
Code
R/W
ACK
S
T
A
R
T
1 0 1 0 X X X
Parameter Register
Device Select
R/W
ACK
Address
Code
00h
Parameter Register
Address
R/W
00h
ACK
ACK
Parameter Register contents until it receives a
NoACK from the I²C Host.
The CRX14 supports the I²C Current Address and
Random Address Read modes. The Current Ad-
dress Read mode can be used if the previous
command was issued to the register where the
Read is to take place.
R
E
S
T
A
R
T
1 0 1 0 X X X
Register Byte
ACK
Device Select
data
Value
Code
Register Byte
data
NoACK
Value
R/W
ACK
S
T
O
P
ACK
Register Byte
S
T
O
P
data
Value
NoACK
CRX14
ai09240
ai09242
ai09241
S
T
O
P
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