Addressing mode

Question

Comments

Consider 2 instructions -
1. Add $R_a,  \ R_b, \  \color{RED}{R_d}$
2. Mul $R_c,  \ \color{RED}{R_d}, \  R_e$

Now, according to underlined line, as the result of instruction 1 is required by instruction 2, so instruction 1 will take 2 clock cycles and instruction 2 will take 1 clock cycle only.

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Okk thank you so much,,

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option C)6

Answer 1

Expression- $XY + XYZ +YZ$
Initially,
$X$ is in $R_0$,
$Y$ is in $R_1$,
$Z$ is in $R_2$.

$MUL \ \ R_0, \ R_1, \  R_4​​​​$    // 1 clock cycle   (XY)
$MUL \ \ R_1, \ R_2, \  R_5​​​$    // 1 clock cycle   (YZ)
$MUL \ \ R_4, \ R_2, \  R_6​​​$    // 1 clock cycle   (XYZ)
$ADD \ \ R_4, \ R_5, \  \color{Red}{R_7}$    // 2 clock cycle   (XY + YZ)
$ADD \ \ \color{Red}{R_7} \ R_6, \  R_8$     // 1 clock cycle   (XY + XYZ + YZ)

Total 6 clock cycles.

Comments

in the question, They Said the content of Ro R1 R2 not modifyied

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why in this order of instructions are executed if we execute I3 then I2 answer will be -  7

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Mam 8 temp registers are there R0 to R7

I know you have not used R3 anywhere and used R8 :) plz change if possible