24、计算机乘法与除法运算的原理与实现

计算机乘法与除法运算的原理与实现

1. 微指令块与操作码

在计算机的底层操作中，微指令块起着关键作用。以下是一些微指令块的示例：

{--- microinstruction block:
sab8:
;ax .- xxxx
Int, Zero, BF, Clk = 1; AX .- 0 + T1; Goto Interp. --}
org x'F7'
;F7 XX for unary operation
SHLIR1 = 1; Addr =100; fJPC .- AddrAOp.
org x' 1DO'
;F7 DO
not ax
Int, Zero, Comp, BF, Clk =1; AX .- .NOT. AX; Goto Interp.
org x'lD8'
;F7 D8
neg ax
Int, Zero, Comp, 8F, Clk, Cin = I; AX .- 0 - AX;
Goto Interp.
org x'EC'
{EC
in aI, dx
;al .- IOR[dx] }
BF = 1; Gota saec.
{--- microinstruction block:
saec:
;Input byte and wait
In, Zero, Clk = 1; lOA .- 0 + OX; fJPC .- J.1PC + 1.
Int = 1; AL .- 0 + 100L; Goto Interp. -- }
org x'EE'
{EE
out dx, al
;IOR[dx].- all
BF = I; Goto saee.
{--- microinstruction block:
saee:
;Output