52
SLOS743L – AUGUST 2011 – REVISED MARCH 2017
Product Folder Links:
Detailed Description
Copyright © 2011–2017, Texas Instruments Incorporated
(1)
Displays the cause of IRQ and TX/RX status
Table 6-18. IRQ Status Register (0x0C) for NFC and Card Emulation Operation
(1)
BIT
NAME
FUNCTION
DESCRIPTION
B7
Irq_tx
IRQ set due to end of TX
Signals that TX is in progress. The flag is set at the start of
TX but the interrupt request (IRQ = 1) is sent when TX is
finished.
B6
Irg_srx
IRQ set due to RX start
Signals that RX SOF was received and RX is in progress.
The flag is set at the start of RX but the interrupt request
(IRQ = 1) is sent when RX is finished.
B5
Irq_fifo
Signals the FIFO level
Signals FIFO high or low as set in the Adjustable FIFO IRQ
Levels (0x14) register
B4
Irq_err1
CRC error
Indicates receive CRC error only if B7 (no RX CRC) of ISO
Control register is set to 0.
B3
Irq_err2
Parity error
Indicates parity error for ISO/IEC 14443 A
B2
Irq_err3
Byte framing or EOF error
Indicates framing error
B1
Irq_col
Collision error
Collision error for ISO/IEC 14443 A and ISO/IEC 15693
single subcarrier. Bit is set if more than 6 or 7 (as defined in
register 0x10) are detected inside 1 bit period of
ISO/IEC 14443 A 106 kbps. Collision error bit can also be
triggered by external noise.
B0
Irq_noresp
No-response time interrupt
No response within the "No-response time" defined in RX
No-response Wait Time register (0x07). Signals the MCU
that next slot command can be sent. Only for
ISO/IEC 15693.
6.13.2 Initiator
The chip is fully controlled by the MCU as in RFID reader operation. The MCU activates the chip and
writes the mode selection in the ISO Control register. The normal transmit and receive procedure (through
the FIFO) are used to communicate with the TARGET device as described in
.
6.14 Direct Commands from MCU to Reader
6.14.1 Command Codes
summarizes the command codes.
Table 6-19. Address and Command Word Bit Distribution
COMMAND
CODE
COMMAND
COMMENTS
0x00
Idle
0x03
Software initialization
Same as Power on Reset
0x04
Perform RF collision avoidance
Does not function as expected. See the
for details.
0x05
Perform response RF collision avoidance
Does not function as expected. See the
for details.
0x06
Perform response RF collision avoidance (n = 0)
Does not function as expected. See the
for details.
0x0F
Reset FIFO
0x10
Transmission without CRC
0x11
Transmission with CRC
0x12
Delayed transmission without CRC
0x13
Delayed transmission with CRC
0x14
End of frame and transmit next time slot
Used for ISO/IEC 15693 only
0x16
Block receiver
0x17
Enable receiver
0x18
Test internal RF (RSSI at RX input with TX off)