Rainbow Electronics MAX66100 - Manual (Page 13)

MAX66100
ISO 15693-Compliant 64-Bit UID
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Detailed Command Descriptions
In the request data graphics of this section, the UID
field is shaded to indicate that the inclusion of the UID
depends on the address mode.
Get System Information
The Get System Information command is the only com-
mand beyond the network function level that the
MAX66100 supports. It allows the master to retrieve
technical information about the MAX66100. The IC ref-
erence code indicates the die revision in hexadecimal
format, such as A1h, A2h, B1h, etc.
CRC Generation
The ISO 15693 standard uses a 16-bit CRC, generated
according to the CRC-16-CCITT polynomial function:
X
16 + X 12 + X 5 + 1 (see Figure 16). This CRC is used
for error detection in request and response data pack-
ets and is always communicated in the inverted form.
After all data bytes are shifted into the CRC generator,
the state of the 16 flip-flops is parallel-copied to a shift
register and shifted out for transmission with the LSb
first. For more details on this CRC, refer to ISO/IEC
15693-3, Annex C.
REQUEST FLAGS COMMAND UID
(1 Byte) 2Bh (8 Bytes)
RESPONSE
FLAGS
INFO
FLAGS
UID DSFID AFI
NUMBER OF
BLOCKS
MEMORY BLOCK
SIZE
IC REFERENCE
00h 0Fh (8 Bytes) (1 Byte) (1 Byte) 00h 07h (1 Byte)
Request Data for the Get System Information Command
Response Data for the Get System Information Command (No Error)
Figure 16. CRC-16-CCITT Generator
1ST
STAGE
MSb
LSb
2ND
STAGE
7TH
STAGE
8TH
STAGE
6TH
STAGE
X 0 X 1
3RD
STAGE
4TH
STAGE
5TH
STAGE
X 2 X 3 X 4
POLYNOMIAL = X 16 + X 12 + X 5 + 1
INPUT DATA
X 5 X 6
11TH
STAGE
X 11
9TH
STAGE
10TH
STAGE
X 9 X 10
12TH
STAGE
15TH
STAGE
14TH
STAGE
13TH
STAGE
X 12 X 13 X 14
X 7
16TH
STAGE
X 16 X 15 X 8