Specifications

TLSB Bus 2-21
Table 2-5 TLSB Data Wrapping
2.2.8.6 ECC Coding
Data is protected using quadword ECC. The 256-bit data bus is divided
into four quadwords. Protection is allocated as follows:
• TLSB_D<63:0> is protected by TLSB_ECC<7:0>
• TLSB_D<127:64> is protected by TLSB_ECC<15:8>
• TLSB_D<191:128> is protected by TLSB_ECC<23:16>
• TLSB_D<255:192> is protected by TLSB_ECC<31:24>
Figure 2-3 shows the ECC coding scheme for TLSB_D<63:0> and
TLSB_ECC<7:0>. The same coding scheme is used for each of the other
three quadwords, and again for the four quadwords in the second data cy-
cle.
Figure 2-3 64-Bit ECC Coding Scheme
TLSB_ADR<5> Data Cycle Data Bytes
0
0 0–31
0
1 32–63
1
0 32–63
1
1 0–31
XOR S7
XOR S6
XOR S5
XOR S4





XNOR S3
XNOR S2
XOR S1
XOR S0

HEX
SYNDROME
6666
3210
0000
1111
1111
1100

0011
1010
0001
1011

7766
50DB


5555
9876
0000
1111
1111
0000

1000
0110-
0101
0100

6666
8742


5555
5432
1111
0000
0000
1111

1110
1001
0101
1101

9999
DB87


5544
1098
1111
0000
0000
1100

0011
1001
0111
0001

9988
42AF


4444
7654
1111
0000
1111
1100

0011
1010
0001
1011

BBAA
50DB


4444
3210
1111
0000
1111
0000

1000
0110
0101
0100

AAAA
8742


3333
9786
0000
1111
0000
1111

1110
1001
0101
1101

5555
DB87

3333
5432

0000
1111
1111
1100

0011
1001
0111
0001

5544
42AF


1111
9876
0000
0000
0000
1100

0011
1001
0111
1110

1100
53BE


1111
5432
0000
0000
1111
1100

0011
1010
0001
0100

3322
41CA


11
1098
0000
0000
1111
0000

1000
0110
0101
1011

2222
9653



7654
1111
1111
0000
1111

1110
1001
0101
0010

DDDD
CA98



3210
1111
1111
0000
1100

0011
1001
0111
1110

DDCC
53BE


CHECK
BITS
XOR S7
XOR S6
XOR S5
XOR S4






7654

1000
0100
0010
0001

0000
0000
0000
0000

8421
0000




3210
0000
0000
0000
0000

1000
0100
0010
0001

0000
8421


DATA
BITS
XNOR S3
XNOR S2
XOR S1
XOR S0

HEX
SYNDROME

3322
1098
1111
1111
1111
1100

0011
1010
0001
0100

FFEE
41CA


2222
7654
1111
1111
1111
0000

1000
0110
0101
1011

EEEE
9653


2222
3210
0000
0000
0000
1111

1110
1001
0101
0010

1111
CA96


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