Assembly: 

CRC32B rt, rs

nanoMIPS. Optional, present when Config5.CRCP=1.

CRC32 Byte.

Purpose:

CRC32 Byte.Generatea32-bit CRC valuebasedonthereversedpolynomial$rt

0xEDB88320,using cumulative 32-bit CRC valueand right-justified byte-sized message$rt $rs as inputs.

Availability:

nanoMIPS. Optional, present when Config5.CRCP=1.

Format:

001000

rt

rs

x

000

1111

1

01

000

6

5

5

3

3

4

1

2

3

Operation: 

if C0.Config5.CRCP == 0:
    raise exception('RI')
result = crc32(value=GPR[rt], message=GPR[rs], nbits=8, poly=0xEDB88320)
GPR[rt] = sign_extend(result, from_nbits=32)

Exceptions:

Reserved Instruction on cores without CRC support.