Consider an Acc$-$ISA CPU that executes the pseudo$-$code shown. Do the following:

$...//$some code

while $\{($true$)//$loop forever

$\{$

T$=(-5-$A$+$B$)^$C; $//$where $^$ stands for bit$-$wise XOR

$...//$some other code $($not given$)$

$\}$

a$.$ Create a set of $8-$bit Acc$-$ISA instructions with $3-$bit op$-$codes and $5-$bit operands. Any of the variables A through C may be a negative $2\text{'}$s complement number.

b$.$ Write an assembly program using your instruction set. Also assume that the code starts from memory address $0$ and increases by $1,$ and data starts from memory address $0$x$1$F and decreases by $1.$

c$.$ Manually assemble your assembly program and write instructions in binary and in hex. Assign op$-$codes to the instructions in the order they were used in the assembly program, starting from address

Hints and Guidelines:

$*$ Refer to the attached table as an example for question $($a$).$

$*$ From the above pseudo$-$code, identify what operations you need to perform. How about ADD, SUB, XOR, etc? For each of these codes assign a $3-$bit opcode. You need $<mtext></mtext><mn>8</mn>$ opcodes and hence you are good with $3$ bits.

$*$ Keep in mind that you can manipulate the ACC, by accessing the operands from memory directly. There are several examples in the book in this regard.

$*$ For question $($a$)$

A table with $3-$bit OPCODE$($s$),$ Instruction$($s$),$ and Action$($s$)$ be listed.

Example:

$000-$ XOR $($address$)$

Assign addresses LD$,$ SUB, ADD, XOR, ST$,$ BR in that order starting with opcode $000.$

$*$ For question $($b$)$

$1)$ You have several examples of code segments and data segments.

$2)$ Start code section address from $0$; Per se$.$ for all the instruction flow $0,1,2,.....$

$3)$ For the $.$data segment it will be $1$ byte of data, and hence all the data variables get stored in the memory with

i$.$ Example:

$0$X$1$F T RB $1$

ii$.$ Order the variables T$,$ A$,$ B$,$ C $--$ in this order.

$*$ For question $($c$),$ you may refer to the assembly code in the provided photo. Note the two columns: Instruction in binary and in Hex.$\backslash$table$[[$Op$-$Code,Instruction,Addressing Mode,Example,Action$],[0,$NOP,,NOP,Do nothing$],[1,$ADD,Immediate,ADD data,ACClarrACC$+$ data$],[2,$Direct,ADD $($address$),$ACClarrACC$+$M $[$address $]],[3,$CMP$,$Immediate,CMP data,$\backslash$table$[[$if ACC$=$ data then GTF$=1$ else$],[$GTF$=0]]],[4,$JGT$,$Immediate,JGT address,PPlarr address if GTF$=1],[5,$JMP$,$Immediate,JMP address,PPlarr address$],[6,$LD$,$Immediate,LD data,ACClarr data$],[7,$Direct,LD $($address$),$ACClarr M$[$address$]],[8,$Indexed,LDX$($address$),$ACClarrM$[$x$+$ address $]],[9,$MVx$,$Register,MVX$,$xlarrACC$],[10,$ST$,$Direct,ST $($address$),$M$[$address$]$ larr ACC$]]$