OpenCores

Rev 38	Rev 66
Line 53...	Line 53...
`b StartTest`	`b StartTest`
`nop`	`nop`


`# Trap handler address`	`# Trap handler address`
`.org 0x3c`	`#.org 0x3c`
	`.org 0x0180`

`# We have three trap sources: syscall, break and unimplemented opcode`	`# We have three trap sources: syscall, break and unimplemented opcode`
`# Plus we have to account for a faulty cause code; that's 4 causes`	`# Plus we have to account for a faulty cause code; that's 4 causes`
`# Besides, we have to look out for the branch delay flag (BD)`	`# Besides, we have to look out for the branch delay flag (BD)`
`# We'll just increment $4 by a fixed constant depending on the cause`	`# We'll just increment $4 by a fixed constant depending on the cause`
`# so we will not save any registers (there's no stack anyway)`	`# so we will not save any registers (there's no stack anyway)`
Line 1098...	Line 1100...
`sb $21,0($20)`	`sb $21,0($20)`

`#d: MTLO`	`#d: MTLO`
`ori $2,$0,'d'`	`ori $2,$0,'d'`
`sb $2,0($20)`	`sb $2,0($20)`
`ori $2,$0,65`	`ori $2,$0,66 # use 'B' instead of 'A' to cach change in HI and LO`
`mtlo $2`	`mtlo $2`
`mflo $3`	`mflo $3`
`sb $3,0($20)`	`sb $3,0($20)`
`sb $23,0($20)`	`sb $23,0($20)`
`sb $21,0($20)`	`sb $21,0($20)`

Line 53...

    b       StartTest

    b       StartTest

nop

nop

    # Trap handler address

    # Trap handler address

    .org    0x3c

    #.org    0x3c

    .org    0x0180

    # We have three trap sources: syscall, break and unimplemented opcode

    # We have three trap sources: syscall, break and unimplemented opcode

    # Plus we have to account for a faulty cause code; that's 4 causes

    # Plus we have to account for a faulty cause code; that's 4 causes

    # Besides, we have to look out for the branch delay flag (BD)

    # Besides, we have to look out for the branch delay flag (BD)

    # We'll just increment $4 by a fixed constant depending on the cause

    # We'll just increment $4 by a fixed constant depending on the cause

    # so we will not save any registers (there's no stack anyway)

    # so we will not save any registers (there's no stack anyway)

Line 1098...

Line 1100...

    sb      $21,0($20)

    sb      $21,0($20)

    #d: MTLO

    #d: MTLO

    ori     $2,$0,'d'

    ori     $2,$0,'d'

    sb      $2,0($20)

    sb      $2,0($20)

    ori     $2,$0,65

    ori     $2,$0,66   # use 'B' instead of 'A' to cach change in HI and LO

    mtlo    $2

    mtlo    $2

    mflo    $3

    mflo    $3

    sb      $3,0($20)

    sb      $3,0($20)

    sb      $23,0($20)

    sb      $23,0($20)

    sb      $21,0($20)

    sb      $21,0($20)

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