Assignment03SolutionFall2010

Assignment03SolutionFall2010 - out ,End 4.5 Write concrete...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
525.412 Computer Architecture Assignment 3 Solutions 4.2 Extend the SRC instruction set by adding the instruction swap ra, rb, (op=7), that exchanges the contents of the two speciFed registers. a. DeFne a plausible abstract RTN for this instruction. b. Develop the concrete RTN for it, assuming the 1-bus SRC microarchitecture. Solution The abstract RTN from problem 2.21 will do: swap(:= op = 7) ( R [ ra ] R [ rb ] : R [ rb ] R [ ra ]) : ±or the concrete RTN, we need a temporary register. We could use MD for this purpose. It is not a good idea to use another general-purpose register for this purpose because then programmers need to be aware that the contents of that register are corrupted by the swap function, never a good idea if it can be avoided. Step Concrete RTN Control Sequence T0-T2 Instruction ±etch T3 MD R[ra] MD bus ,Gra,R out T4 C R[rb] Grb,R out ,C in ,C=B T5 R[ra] C Gra,R in ,C out T6 R[rb] MD R in ,Grb,MD
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: out ,End 4.5 Write concrete RTN steps and control sequences for the not instruction implemented in the 1-bus microarchitecture. Solution The abstract RNT for the not instruction is found on page 63 of the text. not(:= op = 24) R [ ra ] R [ rc ] : Step Concrete RTN Control Sequence T0-T2 Instruction etch T3 C R[rc] Grc,R out ,C in ,NOT T4 R[ra] C Gra,R in ,C out ,End 1 4.8 Using Table 4.6 to 4.11, develop as much as you can of the control signals MD out , C in , and LD. Show both the Boolean equations and the gate-level designs. Solution Assume that LD in the question is the same as Ld in Table 4.10. MD out = T2 + T7 ld C in = T0 + T4 (add + addi + ld) + (T5 + T6 (n n =0)) shr LD = T3 shr + T4 shr (n=0) T0 T2 T3 T4 T5 T6 T7 ld add ld addi n=0 shr out MD in C Ld 2...
View Full Document

This note was uploaded on 11/25/2010 for the course ECE 525.412 taught by Professor Charlesb.cameron during the Spring '10 term at Johns Hopkins.

Page1 / 2

Assignment03SolutionFall2010 - out ,End 4.5 Write concrete...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online