Question: 29. Direct addressing is immediate addressing deferred. Indirect addressing is direct addressing deferred. You can carry this concept one level further with double indirect addressing,

29. Direct addressing is immediate addressing deferred. Indirect addressing is direct addressing deferred. You can carry this concept one level further with double indirect addressing, which is indirect addressing deferred. Implement a new instruction in place of NOP0 with mnemonic STWADI, which stands for store word accumulator double indirect. It should store the accumulator using double indirect addressing. None of the status flags are affected. NOP0 is a unary instruction as far as the assembler and CPU are concerned, but your program must implement it as a nonunary instruction. You will need to increment the saved PC to skip over the operand specifier. Use the test program provided in the Pep/9 app to test the features of the new instruction.

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Principles Algorithms And Systems Questions!