DEMOKITCRX14 STMicroelectronics, DEMOKITCRX14 Datasheet - Page 25

• 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

CRX14
Figure 17. CRX14-to-host transfer: I²C random address read from slot marker register
Figure 18. CRX14-to-host transfer: I²C current address read from slot marker register
5.5
CRX14 Read
Bus Master
Bus Slave
CRX14 Read
Addresses above location 06h
In I²C Write mode, when the CRX14 receives the 8-bit register address, and the address is
above location 06h, the device does not acknowledge (NoACK) and deselects itself from the
bus. The Serial Data line, SDA, stays at logic ‘1’ (pull-up resistor), and the I²C Host receives
a NoACK during the 9th bit time. The SDA line stays High until the STOP condition is issued.
In the I²C Current and Random Address Read modes, when the CRX14 receives the 8-bit
register address, and the address is above location 06h, the device does not acknowledge
the Device Select Code after the START condition, and deselects itself from the bus.
Bus Master
Bus Slave
S
T
A
R
T
1 0 1 0 X X X
Device Select
Code
S
T
A
R
T
1 0 1 0 X X X
R/W
Device Select
ACK
Code
Slot Marker
Register
Address
Doc ID 8880 Rev 4
00h
R/W
ACK
Applying the I²C protocol to the CRX14 registers
ACK
R
E
S
T
A
R
T
FFh
1 0 1 0 X X X
Device Select
NoACK
Code
S
T
O
P
R/W
ACK
FFh
NoACK
ai09248
ai09247
S
T
O
P
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