Altera SerialLite II Protocol - Manual (Page 40)

40 Altera Corporation
SerialLite II Protocol Reference Manual
Data Link Layer Description
Link Management Packet Protection (LMP[7:0])
SerialLite II uses 8 bits of bit interleaved parity (BIP-8) to protect the link
management packet. BIP-8 covers both the link packet type and the link
packet parameter fields, as shown in
Figure 2–19 .
Figure 2–19. BIP-8 Coverage
The BIP-8 is calculated using even parity over all bits of the previous
16-bits of the link management packet payload.
The receiver calculates the syndrome by XORing all link management
packet payload bytes.
In the absence of any errors, the syndrome equals zero.
Effect of Link Management Packet Corruption
A link management packet that has a BIP-8 error is discarded. The impact
of a corrupted link management packet depends on its type.
BIP-8 [7] = LMP Bit[7] = LMP Bit[23] xor LMP Bit[15]
BIP-8 [6] = LMP Bit[6] = LMP Bit[22] xor LMP Bit[14]
BIP-8 [5] = LMP Bit[5] = LMP Bit[21] xor LMP Bit[13]
BIP-8 [4] = LMP Bit[4] = LMP Bit[20] xor LMP Bit[12]
BIP-8 [3] = LMP Bit[3] = LMP Bit[19] xor LMP Bit[11]
BIP-8 [2] = LMP Bit[2] = LMP Bit[18] xor LMP Bit[10]
BIP-8 [1] = LMP Bit[1] = LMP Bit[17] xor LMP Bit[9]
BIP-8 [0] = LMP Bit[0] = LMP Bit[16] xor LMP Bit[8]
Syndrome [7] = LMP Bit[23] xor LMP Bit[15] xor LMP Bit[7]
Syndrome [6] = LMP Bit[22] xor LMP Bit[14] xor LMP Bit[6]
Syndrome [5] = LMP Bit[21] xor LMP Bit[13] xor LMP Bit[5]
Syndrome [4] = LMP Bit[20] xor LMP Bit[12] xor LMP Bit[4]
Syndrome [3] = LMP Bit[19] xor LMP Bit[11] xor LMP Bit[3]
Syndrome [2] = LMP Bit[18] xor LMP Bit[10] xor LMP Bit[2]
Syndrome [1] = LMP Bit[17] xor LMP Bit[9] xor LMP Bit[1]
Syndrome [0] = LMP Bit[16] xor LMP Bit[8] xor LMP Bit[0]
Type BIP-8
BIP-8 Coverage
Parameter