The $8-$bit Motorola $6800$ microprocessor is to be utilized in the development of a microprocessor board. The system is proposed to contain a ROM, a RAM, an input port, and an output port that are mapped into the CPU$$s memory space, according to the specifications given in the table below.

Device Size Desired Base Address

ROM $(27$C$64)8$ KB $$0000$

RAM $(6116)2$ KB $$4000$

Input $(74$LS$244)1$ Byte $$6000$

Output $(74$LS$374)1$ Byte $$7000$

Which one of the following does NOT reflect the characteristics of the $$mapping$$ possessed by the microprocessor system above?

I. With the mapping, not all instructions which reference to memory can be used

for I$/$O devices

II$.$ The mapping has specific$/$dedicated instructions to communicate with I$/$O

devices

III. The mapping takes space $($for I$/$O devices$)$ from the main memory, reducing the

available memory

IV$.$ With the mapping, any I$/$O devices are treated as memory locations on the map

V$.$ With the mapping, any I$/$O devices use separate memory space

Question $25$ Answer

a$.$

I, II$,$ and V only

b$.$

I and II only

c$.$

I and III only

d$.$

I, II and IV only