1. What are some benefits to memory mapped I/O?

2. Name a chip that has no explicit I/O instructions.

3. What term do we use for explicit I/O using IN and OUT instructions?

4. Are the memory words assigned to a particular I/O device contiguous?

5. How is the actual physical memory involved when the CPU issues an I/O instruction to a peripheral via memory-mapped I/O?

6. What kind of circuit is needed to decide who should pay attention to which signals or commands on the system bus?

7. In addition to the above circuit, what wire must exist to alert the device that it should pay attention to the commands on the system bus?

8. If 8 words of memory are allocated to a device, what size of decoder is needed in the device?

9. Draw a logic diagram showing the gates needed to set the device active wire high for a device whose 8 memory words go from address 00001000 to 00001111.

10. What differences are there in the assembler program that communicates with peripherals? We are comparing memory-mapped I/O to isolated I/O.

11. In the following program, which instructions check to see if the data ready bit is turned on?

     CHECKCTL: LOD  1000
               SUB  "01"b
               JNZ  CHECKCTL
               LOD  1001
               STD  X
               LDI  "11"b
               STD  1000
               JMP  CHECKCTL

12. In the above program, how does the CPU tell the peripheral that it received the data byte and the peripheral should continue on to the next byte?