mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 627

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

Transpose and complement operations are performed "on the fly" while reading or
writing values. See
28.3.2.2 32-bit CRC
Compute a 32-bit CRC with the following steps:
Transpose and complement operations are performed "on the fly" while reading or
writing values. See
28.3.3 Transpose feature
By default, the transpose feature is not enabled. However, some CRC standards require
the input data and/or the final checksum to be transposed. The user software has the
option to configure each transpose operation separately, as desired by the CRC standard.
The data is transposed "on the fly" while being read or written.
Freescale Semiconductor, Inc.
3. Write a 16-bit polynomial to the GPOLY[LOW] field. The GPOLY[HIGH] field is
4. Set the CTRL[WAS] bit to program the seed value.
5. Write a 16-bit seed to CRC[LU:LL]. CRC[HU:HL] are not used.
6. Clear the CTRL[WAS] bit to start writing data values.
7. Write data values into CRC[HU:HL:LU:LL]. A CRC is computed on every data
8. When all values have been written, read the final CRC result from CRC[LU:LL].
1. Set the CTRL[TCRC] bit to enable 32-bit CRC mode.
2. Program the transpose and complement options in the CTRL register as required for
3. Write a 32-bit polynomial to GPOLY[HIGH:LOW].
4. Set the CTRL[WAS] bit to program the seed value.
5. Write a 32-bit seed to CRC[HU:HL:LU:LL].
6. Clear the CTRL[WAS] bit to start writing data values.
7. Write data values into CRC[HU:HL:LU:LL]. A CRC is computed on every data
8. When all values have been written, read the final CRC result from
not usable in 16-bit CRC mode.
value write, and the intermediate CRC result is stored back into CRC[LU:LL].
the CRC calculation. See
value write, and the intermediate CRC result is stored back into
CRC[HU:HL:LU:LL].
CRC[HU:HL:LU:LL]. The CRC is calculated bytewise, and two clocks are required
to complete one CRC calculation.
Transpose feature
Transpose feature
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Transpose feature
and
and
Preliminary
CRC result complement
CRC result complement
and
CRC result complement
Chapter 28 Cyclic Redundancy Check (CRC)
for details.
for details.
for details.
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