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Endianness

 

 

 

Figure 71. EN = 0 (Big-Endian Mode) Rate = 3/4

 

 

 

 

Word

 

 

 

 

Word

 

 

 

 

N

 

 

 

 

N + 1

 

 

SP4

SP3

SP2

SP1

SP0

SP9

SP8

SP7

SP6

SP5

0

0

0

A0

X0

0

0

0

0

X1

 

 

Word

 

 

 

 

Word

 

 

 

 

N + 2

 

 

 

 

N + 3

 

 

SP4

SP3

SP2

SP1

SP0

SP9

SP8

SP7

SP6

SP5

0

0

0

0

X2

0

A3'

0

0

X3

 

 

Word

 

 

 

 

Word

 

 

 

 

N + 4

 

 

 

 

N + 5

 

 

SP4

SP3

SP2

SP1

SP0

SP9

SP8

SP7

SP6

SP5

0

0

0

0

X4

0

0

0

0

X5

7.1.1Hard Decision Data

1.OUT_ORDER = 0 EN = 1 (Little-Endian Mode)

OUT_ORDER = 0 results in ordering the hard decision data from 0 to 31 in the 32-bit word output.

Figure 72. Source of Endianness Manager - Ordering of Hard Decisions in 32-Bit Word

(OUT_ORDER = 0)

63

62

32

31

1

0

Stage

Stage

Stage

Stage

Stage

Stage

N

N - 1

N - 31

N - 32

N - 62

N - 63

Figure 73. Destination of Endianness Manager - Ordering of Hard Decisions in 32-Bit Word

(OUT_ORDER = 0)

63

62

32

31

1

0

Stage

Stage

Stage

Stage

Stage

Stage

N

N - 1

N - 31

N - 32

N - 62

N - 63

2.OUT_ORDER = 1 EN = 1 (Little-Endian Mode)

OUT_ORDER = 1 results in ordering the hard decision data from 32 to 0 in the 32-bit word output.

Figure 74. Source of Endianness Manager - Ordering of Hard Decisions in 32-Bit Word

(OUT_ORDER = 1)

63

62

32

31

1

0

Stage

Stage

Stage

Stage

Stage

Stage

N

N - 1

N - 31

N - 32

N - 62

N - 63

Figure 75. Destination of Endianness Manager - Ordering of Hard Decisions in 32-Bit Word

(OUT_ORDER = 1)

63

62

32

31

1

0

Stage

Stage

Stage

Stage

Stage

Stage

N - 31

N - 30

N

N - 63

N - 33

N - 32

3. OUT_ORDER = 0, EN = 0 (Big-Endian Mode)

Figure 76. Source of Endianness Manager - Trellis Stage Ordering of Hard Decisions in 32-Bit Word

(OUT_ORDER = 0)

63

62

32

31

1

0

Stage

Stage

Stage

Stage

Stage

Stage

N

N - 1

N - 31

N - 32

N - 62

N - 63

SPRUGK1–March 2009

TMS320C6457 Turbo-Decoder Coprocessor 2

53

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Texas Instruments TMS320C6457 DSP manual EN = 0 Big-Endian Mode Rate = 3/4, Hard Decision Data