
AT88RF1354 SPI User Guide For CryptoRF
®
4.4
AT88RF1354 Register Bit Coding Summary
The bit coding for the write-able AT88RF1354 register fields is summarized below. Refer to the
AT88RF1354 Command Reference Guide
for detailed information.
4.4.1
FWI:
Frame Waiting Interval. Used to select the time the reader waits for a response to begin
after a command is transmitted. The Frame Waiting Time (FWT) is calculated from FWI using the
formula in the un-amended ISO/IEC14443-3 base standard.
When communicating over the RF channel the CPR field of the command is used to select a CPR
register set to configure the reader. By storing the timeout setting in the CPR registers it is only
necessary to configure the RF protocol once. A transaction can contain a series of commands
with different response times; as the reader executes each command it reconfigures the
transceiver instantly to the settings in the specified CPR. Transaction time is optimized by
specifying FWI no longer than necessary for each PICC operation
4.4.2
RFU:
Reserved for Future Use. All RFU bits must contain 0 b.
Table 7.
Coding of Frame Waiting Time in FWI Field
Bit 7
Bit 6
Bit 5
Bit 4
FWT
FWT Time
0 0 0 0
32
ETUs
302.1
uS
0 0 0 1
64
ETUs
604.1
uS
0 0 1 0
128
ETUs 1,208.3
uS
0 0 1 1
256
ETUs 2,416.5
uS
0 1 0 0
512
ETUs 4,833.0
uS
0 1 0 1
1024
ETUs 9,666.1
uS
0 1 1 0
2048
ETUs 19,332.2
uS
0 1 1 1
4096
ETUs 38,664.3
uS
1 0 0 0
8192
ETUs 77,328.6
uS
1 0 0 1 16384
ETUs
154,657.2
uS
1 0 1 0 32768
ETUs
309,314.5
uS
1 0 1 1 65536
ETUs
618,628.9
uS
1 1 0 0 131072
ETUs
1,237,257.8
uS
1 1 0 1 262144
ETUs
2,474,515.6
uS
1 1 1 0 524288
ETUs
4,949,031.3
uS
1 1 1 1
RFU RFU
4-4
8586A—RFID—5/09