mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 624

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

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Memory map and register descriptions
28.2.2 CRC Polynomial Register (CRC_GPOLY)
This register contains the value of the polynomial for the CRC calculation. The HIGH
field contains the upper 16 bits of the CRC polynomial, which are used only in 32-bit
CRC mode. Writes to the HIGH field are ignored in 16-bit CRC mode. The LOW field
contains the lower 16 bits of the CRC polynomial, which are used in both 16- and 32-bit
CRC modes.
Address: CRC_GPOLY is FFFF_8570h base + 4h offset = FFFF_8574h
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Bit
W
R
31
0
31–16
HIGH
LOW
15–8
15–0
Field
Field
7–0
LU
LL
30
0
29
0
28
0
CTRL[WAS] bit is 1. When the CTRL[WAS] bit is 0, data written to this field is used for CRC checksum
generation in both 16-bit and 32-bit CRC modes.
CRC Low Upper Byte
When the CTRL[WAS] bit is 1, values written to this field are part of the seed value. When the
CTRL[WAS] bit is 0, data written to this field is used for CRC checksum generation.
CRC Low Lower Byte
When the CTRL[WAS] bit is 1, values written to this field are part of the seed value. When the
CTRL[WAS] bit is 0, data written to this field is used for CRC checksum generation.
High polynominal half-word
This field is writable and readable in 32-bit CRC mode (the CTRL[TCRC] bit is 1). This field is not writable
in 16-bit CRC mode (the CTRL[TCRC] bit is 0).
Low polynominal half-word
This field is writable and readable in both 32-bit and 16-bit CRC modes.
27
0
26
0
25
0
24
HIGH
0
CRC_CRC field descriptions (continued)
MCF51JF128 Reference Manual, Rev. 2, 03/2011
23
0
22
0
CRC_GPOLY field descriptions
21
0
20
0
19
0
18
0
Preliminary
17
0
16
0
15
0
Description
Description
14
0
13
0
12
1
11
0
10
0
0
9
LOW
0
8
Freescale Semiconductor, Inc.
0
7
0
6
1
5
4
0
0
3
0
2
0
1
1
0