Digital Electronics - Microprocessor Fundamentals - Discussion

Memory Mapped I/O:

- 16-bit device address.
- Data transfer between any general-purpose register and I/O port.
- The memory map (64K) is shared between I/O device and system memory.
- More hardware is required to decode the 16-bit address.
- The arithmetic or logic operation can be directly performed with I/O data .

Peripheral Mapped I/O:

- 8-bit device address.
- Data is transfer only between accumulator and I.O port.
- The I/O map is independent of the memory map; 256 input device and 256. the output device can be connected.
- Less hardware is required to decode the 8-bit address.
- Arithmetic or logical operation cannot be directly performed with I/O data.

Memory mapped I/O mean connecting of external memory device to the processor.

There are two ways to assign a address of I/O.

1) peripheral I/O.
2) memory mapped I/O.

In peripheral I/O, 8 bit address lines are there for assigning.
And in memory mapped I/O, 16 bit address lines are there for assigning.

Memory mapping mean the process of interfacing memory with micro processor. And allocating adress for each memory location.

In memory mapped I/o the address are shared. it means some address of memory provide to I/O devices. note that same address doesnot assign to memory or i/o device.

Can anyone define the above defnitions?