AT88RF1354 SPI User Guide For CryptoRF
3.10.2 Example
String Decode > O000C Host sends twelve bytes thru microcontroller to AT88RF1354 serial port.
>
03
AT88RF1354 TX Data command.
>
08
Data bytes sent to PICC. In this example 8 bytes are sent to the PICC.
>
02
PARAM. Bits[2:0] select AT88RF1354 Communication Protocol Register 2 (CPR2).
>
00
Timeout. A $00 selects the Frame Waiting Interval defined during CPR initialization.
>
14
To PICC: Write System Command. Upper nibble is CID assigned in ATTRIB command. Lower nibble is $4.
>
00
To PICC: PARAM = $00. A $00 selects the write system zone PARAM option.
>
00
To PICC: ADDR. Starting address of location to be written.
>
03
To PICC: "L". "L" is the number of bytes to write minus 1.
>
12
To PICC: Data 1.
>
34
To PICC: Data 2.
>
56
To PICC: Data "L"
>
78
To PICC: Data "L + 1"
Wait for AT88RF1354 ISTAT pin state.
ISTAT goes High.
The AT88RF1354 buffer has data ready. Data must be read before the next command can be issued.
>
I0006 Host gets six bytes from AT88RF1354 buffer.
>
00
AT88RF1354 Response: $00 (No RF communication error bits set in the EREG register).
>
03
AT88RF1354 Response: PICC response byte count.
>
02
AT88RF1354 Response: PARAM. Echo PARAM byte used in prior TX Data command.
>
14
PICC Response: Upper nibble is CID assigned in ATTRIB command. Lower nibble is $4.
>
00
PICC Response: PICC ACK/NACK. ACK is $00, the command executed correctly.
>
00
PICC Response: PICC status code. Status message $00 is no errors.
The AT88RF1354 automatically strips the RF communication CRC bytes.
ISTAT stays Low.
The AT88RF1354 buffer is empty. The AT88RF1354 will now accept a new command.
3.10.3 Operation
The Write System Zone command writes data into the configuration memory. As each byte is
clocked into the memory the lower bits of the address are internally incremented. The upper
address bits are not incremented, so the page address remains constant.
Write operations cannot cross page boundaries. A Write System Zone command can only write
data bytes within a single physical memory page. Attempts to write beyond the end of page
boundary will wrap to the beginning of the same page. Only PICCs in the Active State are
permitted to answer this command.
A special mode of the Write System Zone programs the security fuses. Once programmed, the
fuses cannot be erased.
The Check Password command must be successfully executed prior to writing the system zone.
3-19
8586A—RFID—5/09
