Question

Give the bit pattern for the instruction LDWX 0x54C1,d

that instruction is in Assembly Language

Answer 1

First 8 bits for LDA will be 1100 raaa.

from them,
First 4 bits,
Instruction specifier for LDA instruction is 1100.

For 5th bit,
if it is accumulator then 1 and if index register then 0.
Here index register X is used. So, r = 1 means 5th bit will be 1.

Other 3 bits(6, 7 and 8) represents addressing mode. d from given instruction soecifies direct addressing mode.
For direct addressing aaa = 001.
Thus,

Fisrt 8 bits will be 1100 1001

Here hexadecimal constant is 54C1. Thus other bits are 0101 0100 1100 0001.

Thus, final bit pattern for LDWX 0x54C1, d will be
1100 1001 0101 0100 1100 0001.