Question

1.)

a.) Using the simplified instruction set shown for part b, write code for the following. Suppose memory locations 1400 to 1449 contain 16-bit words. Each word represents 2 ASCII characters. Write code to read in and write out these 100 characters. Left-side character from location 1400 should be first, right-side character from location 1400 should be second, and remaining characters follow in numeric order. Assume you have access to 4 registers: R1, R2, R3, R4. Each register holds one word (16 bits). Number the lines of your operations starting with 1.

b.) In the following table, place ‘X’s in columns to indicate the addressing mode(s) used for each instruction.

Operation Name	Description	Immediate	Direct	Indirect	Register	Register Indirect	Displacement	Stack
MOVE X,K	Move constant K to register X
LOAD X,Y	Move contents at address contained in register Y to register X
STORE A,X	Store contents at register X to address A
CLEAR X	Transfer word of 0s to register X
SET X	Transfer word of 1s to register X
PUSH X	Transfer contents of register X to top of stack*
POP X	Transfer contents of top of stack to register X*
ADD X,Y	Replace contents of X with X + Y (contents)
SUB X,Y	Replace contents of X with X - Y (contents)
MULT X,Y	Replace contents of X with X * Y (contents)
DIVIDE X,Y	Replace contents of X with X / Y (contents)
ABS X	Replace contents of X with |X| (contents)
NEG X	Replace contents of X with -X (contents)
INCR X	Replace contents of X with X + 1 (contents)
DECR X	Replace contents of X with X +-1 (contents)
AND X,Y	Replace contents of X with bitwise AND of X and Y (contents)
OR X,Y	Replace contents of X with bitwise OR of X and Y (contents)
NOT X	Replace contents of X with bitwise negation of X (contents)
XOR X,Y	Replace contents of X with bitwise XOR of X and Y (contents)
LSHIFTR X,K	Replace contents of X with logical shift right of X (contents) by K bits
LSHIFTL X,K	Replace contents of X with logical shift left of X (contents) by K bits
ASHIFTR X,K	Replace contents of X with arithmetic shift right of X (contents) by K bits
ASHIFTL X,K	Replace contents of X with arithmetic shift left of X (contents) by K bits
ROTR X,K	Replace contents of X with rotate right of X (contents) by K bits
ROTL X,K	Replace contents of X with rotate left of X (contents) by K bits
UBRANCH K	Unconditionally branch to instruction on line K (K is a constant)
CZBRANCH K,X	Conditionally branch to instruction on line K (K is a constant) if X=0 (contents)
INPUT X	Fill contents of X with data from I/O processor
OUTPUT X	Send contents of X to I/O processor

Answer 1

Regis Operat ion Name Description ter Immed Dindir RegisIndirDisplaceSta iate ect ect ter ect ment MOVE Move constant K to register X LOADMove contents at address contained X,Y in register Y to registerX STORE Aメ Store contents at register X to address A CLEAR Transfer word of Os to register X SETX Transfer word of 1s to register X PUSH Transfer contents of register X to top of stack* Transfer contents of top of stack to register POP X Replace contents of X with X+ Y (contents) ADD X,Y SUB Replace contents of X with X-Y (contents) X,Y MULT Replace contents of X with X* Y