Controlling the Execution of Jump and Branch
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Jump (
j)
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(1) “
J=1” selects Imm26 as jump target address according to the Next PC block;
(2) “PCSrc=1”selects jump target address;
(3) upper 4 bits are from the incremented PC; and
(4) MemRead, MemWrite, and RegWrite are 0.
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Branch on Equal (
beq) or Branch on Not Equal (bne)
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(1) Either “
Beq=1” or “Bne=1 ”;
(2) “ALUSrc=0” ( the second ALU input is BusB);
(3) “ALUCtrl=‘SUB’” produces zero flag; and
(4) MemRead, MemWrite, and RegWrite are 0 according to the Next PC block.
