Questions

  1. What do all control instructions have in common?

  2. What two inputs does the DRMUX have?

  3. Assemble the following BR instruction:
    x326E LOOP ADD R0, R0, #1
    .
    .
    x3321 BRnz LOOP

  4. What is a TRAP?

  5. Why do we need the TRAP instruction?

  6. What is the BIOS?

  7. What's stored in the trapvec8?

  8. What's stored in the trap vector table?

  9. What does the EXTERNAL tag do?

  10. What happens during the first pass of compilation?

Assembling

Give, in hex, the machine instruction in each of the following situations:

x0295: BRnz LABEL
...
x0306: LABEL GETC

x0386: START .FILL 0x3000
...
x03D5: JSR START

x0295: JSRR R7

0x5023: JMP R3