Suppose the MIPS ALU, in addition to a zero flag output, also has an additional

Question

Suppose the MIPS ALU, in addition to a zero flag output, also has an additional flag output for negative which equals 1 whenever the computation result of the ALU is negative (i.e., has high-order bit set to 1. Show how to modify the data path to include, in addition to beq, the branch instructions bne (branch if not equal), bltz (branch if less than 0), and bgez (branch if greater than or equal to 0). You may assume the following: Control produces an additional 2-bit output, Branch Type that equals 00 for beq, 01 fo bne, 10 for bltz and 11 for bgez. The branch instructions bltz and bgez will make the second input register equal the $zero register. Hint: the circuitry that determines whether or not to take the branch (ie., the conditional that feeds into the MUX making that determination) gets a bit more complicated

Explanation / Answer

1.

beq $zero, 00, loop

bne $zero, 01, loop

bltz $zero, 10, loop

bsez $zero, 11, loop

2.

bltz $zero, $t, $t=$zero

bgez $zero, $t, $t=$zero

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.