TSK3000A Core Instruction - BLTZ

Instruction:

Branch On Less Than Zero

Assembler Format:

bltz rA, target

Example:

bltz $3, _myfunc

Description:

Generates a branch target address by adding the address of the instruction in the delay slot to a signed offset (a 16-bit immediate value, IMM16, calculated from the target operand, left-shifted two bits and sign-extended to 32 bits). If the value in GPR rA is negative (i.e. the sign bit of rA is 1), the program branches to the target address after a delay of one instruction cycle.

Operation:

If rA < 0 Then
   PC <-- PC + 4 + SignExtend(IMM16 * 4)
Else
   PC <-- PC + 4

Instruction Type:

I-Type

Instruction Fields:

rA = Register index of operand A

target = a symbolic address label or a hard-coded PC-offset in bytes