mfrc531 NXP Semiconductors, mfrc531 Datasheet - Page 66

• Manufacturer Part Number: mfrc531
• Description: Iso/iec 14443 Reader Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
MFRC531_34
Product data sheet
PUBLIC
10.5.5.4 CRCPresetLSB register
10.5.5.5 CRCPresetMSB register
10.5.5.6 PreSet25 register
Table 99.
[1]
LSB of the preset value for the CRC register.
Table 100. CRCPresetLSB register (address: 23h) reset value: 0101 0011b, 63h bit allocation
Table 101. CRCPresetLSB register bit descriptions
MSB of the preset value for the CRC register.
Table 102. CRCPresetMSB register (address: 24h) reset value: 0101 0011b, 63h bit
Table 103. CRCPresetMSB bit descriptions
Table 104. PreSet25 register (address: 25h) reset value: 0000 0000b, 00h bit allocation
Remark: These values must not be changed.
Bit
1
0
Bit
Symbol
Access
Bit
7 to 0
Bit
Symbol
Access
Bit
7 to 0 CRCPresetMSB[7:0]
Bit
Symbol
Access
When used with ISO/IEC 14443 A, this bit must be set to logic 1.
Symbol
Symbol
ParityOdd
ParityEn
Symbol
CRCPresetLSB[7:0]
ChannelRedundancy bit descriptions
allocation
7
7
7
1
Value
0
1
0
Rev. 3.4 — 26 January 2010
6
6
6
Function
odd parity is generated or expected
even parity is generated or expected
a parity bit is inserted in the transmitted data stream after each byte
and expected in the received data stream after each byte (MIFARE,
ISO/IEC 14443 A)
no parity bit is inserted or expected (ISO/IEC 14443 B)
5
056634
Description
defines the starting value for CRC calculation. This value is
loaded into the CRC at the beginning of transmission, reception
and the CalcCRC command (if the CRC calculation is enabled)
Remark: This register is not relevant if CRC8 is set to logic 1.
Description
defines the start value for CRC calculation. This value is loaded
into the CRC at the beginning of transmission, reception and
the CalcCRC command (if CRC calculation is enabled).
5
5
CRCPresetMSB[7:0]
CRCPresetLSB[7:0]
4
4
4
0000000
…continued
R/W
R/W
RW
3
3
3
[1]
ISO/IEC 14443 reader IC
2
2
2
MFRC531
© NXP B.V. 2010. All rights reserved.
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