14-26
DSP56305 User’s Manual
MOTOROLA
CYCLIC CODE CO-PROCESSOR
Programming Considerations
14.6.5
Parity Coding Processing
Parity Coding processing is enabled when the CCOP is programmed to operate in one of
the Parity Coding modes (i. e., if OPM1 = 1). The processing flow is identical in both
Parity Coding modes.
The only difference between the two is that when OPM[1:0] = 11, two CFSRs (CFSRA
and CFSRB) are concatenated together to form one big CFSR with up to 48 stages. The
unused CFSRs are disabled to reduce power consumption.
The Parity Coding mode using one CFSR (OPM[1:0] = 10) is used to calculate the Cyclic
Redundancy Code (CRC) syndrome with a generator polynomial of up to 24 stages
(maximum degree of 24). This mode is basically used for the calculation of the Frame
Check Sequence (FCS) of a data block prior to transmission, or for the calculation of the
CRC for error detection of a received data block. In this mode only the first CFSR
(CFSRA) is enabled for shifts. It is possible to implement Fire coding and decoding for
burst error correction using this mode if the generator polynomial is of degree of 24 or
less. However, in practice, fire codes use higher degree generator polynomials, and they
can be implemented using Parity Coding mode with two concatenated CFSRs (OPM[1:0]
= 11).
The Parity Coding mode using two concatenated CFSRs (OPM[1:0] = 11) is used to
calculate the Cyclic Redundancy Code (CRC) syndrome with a generator polynomial of
up to 48 stages (maximum degree of 48). In practice, this mode is used for Fire coding
and decoding of burst error correction. The Fire coding is identical to FCS calculation
with generator polynomial of degree up to 48. In Fire decoding, the CCOP implements a
pre-multiply calculation and a zero detect function, and upon completion it provides the
DSP programmer with useful data for computing the burst location and the burst error
correction sequence.
Table summarizes the operations being conducted at the input and run phases in every
(enabled) CFSR during a Parity Coding processing session.
Table 14-8
Operations During Parity Coding Processing
Input Phase
Run Phase
Input Data
Enabled if INEx in CSFTB set
Disabled
Shifts
Enabled
Enabled
Summary of Contents for DSP56305
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Page 41: ...MOTOROLA DSP56305 User s Manual 1 1 SECTION 1 DSP56305 OVERVIEW ...
Page 58: ...1 18 DSP56305 User s Manual MOTOROLA DSP56305 Overview DSP56305 Architecture Overview ...
Page 59: ...MOTOROLA DSP56305 User s Manual 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 98: ...2 40 DSP56305 User s Manual MOTOROLA Signal Connection Descriptions JTAG OnCE Interface ...
Page 99: ...MOTOROLA DSP56305 User s Manual 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 119: ...MOTOROLA DSP56305 User s Manual 4 1 SECTION 4 CORE CONFIGURATION ...
Page 144: ...4 26 DSP56305 User s Manual MOTOROLA Core Configuration JTAG Boundary Scan Register BSR ...
Page 145: ...MOTOROLA DSP56305 User s Manual 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 149: ...HOST INTERFACE HI32 MOTOROLA DSP56305 User s Manual 6 1 SECTION 6 HOST INTERFACE HI32 ...
Page 150: ...6 2 DSP56305 User s Manual MOTOROLA HOST INTERFACE HI32 ...
Page 259: ...MOTOROLA DSP56305 User s Manual 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 315: ...MOTOROLA DSP56305 User s Manual 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 347: ...MOTOROLA DSP56305 User s Manual 9 1 SECTION 9 TIMER EVENT COUNTER ...
Page 376: ...9 30 DSP56305 User s Manual MOTOROLA Timer Event Counter Timer Modes of Operation ...
Page 377: ...MOTOROLA DSP56305 User s Manual 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 411: ...MOTOROLA DSP56305 User s Manual 11 1 SECTION 11 JTAG PORT ...
Page 430: ...11 20 DSP56305 User s Manual MOTOROLA JTAG Port DSP56305 Boundary Scan Register ...
Page 431: ...Filter Co Processor MOTOROLA DSP56305 User s Manual 12 1 SECTION 12 FILTER CO PROCESSOR ...
Page 471: ...VITERBI CO PROCESSOR MOTOROLA DSP56305 User s Manual 13 1 SECTION 13 VITERBI CO PROCESSOR ...
Page 522: ...13 52 DSP56305 User s Manual MOTOROLA VITERBI CO PROCESSOR References ...
Page 554: ...14 32 DSP56305 User s Manual MOTOROLA CYCLIC CODE CO PROCESSOR Configuration Examples ...
Page 555: ...MOTOROLA DSP56305 User s Manual A 1 APPENDIX A BOOTSTRAP CODE ...
Page 568: ...A 14 DSP56305 User s Manual MOTOROLA Bootstrap Code ...
Page 569: ...Equates MOTOROLA DSP56305 User s Manual B 1 APPENDIX B EQUATES ...
Page 589: ...MOTOROLA DSP56305 User s Manual C 1 APPENDIX C JTAG BSDL ...
Page 590: ...C 2 DSP56305 User s Manual MOTOROLA JTAG BSDL ...
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Page 601: ...MOTOROLA DSP56305 User s Manual D 1 APPENDIX D PROGRAMMING REFERENCE ...
Page 602: ...D 2 DSP56305 User s Manual MOTOROLA PROGRAMMING REFERENCE ...
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