HTSICH4801EW/V1,00 NXP Semiconductors, HTSICH4801EW/V1,00 Datasheet - Page 45

• Manufacturer Part Number: HTSICH4801EW/V1,00
• Description: RFID Modules & Development Tools Transponder Wafer
• Manufacturer: NXP Semiconductors

Specifications of HTSICH4801EW/V1,00

• Operating Temp Range: -25C to 85C
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935282034005

Philips Semiconductors
13 DATA INTEGRITY / CALCULATION OF CRC
The following explanations show the features of the
HITAG S protocol to protect read and write access to
transponders from undetected errors.
13.1
Every data stream transmitted by the Read/Write Device to
the HITAG S Transponder includes an 8 Bit Cyclic
Redundancy Check (CRC 8).
The data stream is first checked for data errors by the
HITAG S Transponder and then executed.
The generator polynomial for the CRC 8 is:
u
The CRC pre set value is: 0xFF
13.2
13.2.1
The HITAG S Transponder response does not include any
check sum because of flexibility reasons. To get the data
integrity required by the application, check sums have to
be calculated by the user software and stored together
with the information in the transponder memory. This
seems uncomfortable, because the check sums use a little
part of the available memory space in the transponder.
The advantage of this solution is the flexibility to choose
large checksums for applications requiring high data
integrity and smaller check sums for applications requiring
short access times which means short protocols.
13.2.2
In Advanced – and Fast Advanced Response Protocol
Mode the response on a SELECT (UID), CHALLENGE,
READ PAGE, READ BLOCK command, includes a CRC 8
check sum.
The generator polynomial for the CRC 8 is:
u
The CRC pre set value is: 0xFF
8
8
HITAG S
+ u
+ u
4
4
Data Transmission: Read/Write Device to
HITAG S Transponder
Data Transmission: HITAG S Transponder to
Read/Write Device
+ u
+ u
S
A
P
TANDARD
DVANCED
ROTOCOL
3
3
+ u
+ u
2
2
+ 1 = 0x1D
+ 1 = 0x1D
/F
R
M
ESPONSE
AST
ODE
A
DVANCED
P
ROTOCOL
R
ESPONSE
M
ODE
45
HTS IC H32/HTS IC H56/HTS IC H48
Product Specification Revision 3.1 2006 July 18
PUBLIC INFORMATION