Not possible, both are numbers.
Memory mapped IO is one where the processor and the IO device share the same memory location(memory) while IO mapped IO is one where the processor and the IO device have different memory located to each other.
To read and write to I/O
There are 256 ports available in the 8085 microprocessor. The IN and OUT instructions have an 8-bit port number, and that is where the 256 comes from.In order to use ports, the hardware addressing system must decode IO/M-. Some implementations don't do this, so they map IO addresses to memory addresses. In that case, you could say there are 65536 possible IO addresses, but that is not the same as ports, because ports are specific to the IN and OUT instructions.The other "problem" with IN and OUT is that you cannot specify the address in a register, while you can do so with indirect memory addressing.
Memory mapped IO uses a portion of RAM to handle IO requests. In this manner, instructions the CPU uses for reading and writing memory can also be used for IO, reducing the circuitry needed. This makes the CPU simpler, cheaper and more effecient.
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Two potentially competing relationships for IO addresses are obtaining intelligence information required to protect national security and protecting individual right guaranteed by the Constitution and the laws of the United States.
The 8085 only supports an 8 bit address bus when it comes to IO. The range of valid addresses, for IO, is 0 to 255.
A memory mapped IO device is an IO device that responds to a specific address when IO/M- is low. A peripheral (or IO) mapped IO device is an IO device that responds to a specific address when IO/M- is high.Many system designers ignore IO/M- in favor of memory mapped IO.This eliminates one term in the chip select logic for every device.This allows you to use all addressing modes and instructions when manipulating an IO device, as opposed to using only IN and OUT.This allows you to potentially have more than 256 different IO devices.The downside is that you reduce the addressable main memory in the system, i.e. you cannot have all 64K available to you, but this is not generally a problem in most controller designs. You also must decode 16 address lines instead of just 8 when accessing the device.
disadvantages of interrupt
In memory mapped I/O, a chunk of the CPU's address space is reserved for accessing I/O devices. In I/O mapped I/O, I/O devices are handled distinctly by the CPU and hence occupy a separate chunk of addresses predetermined by the CPU for I/O. In case of Memory mapped I/O the same address BUS is used for accessing both Memory (RAM) and the Registers of I/O devices. For I/O Mapped I/O, separate address BUS is used. As Address space is generally larger for Memory than I/O registers, the length of I/O address is larger in case of Memory Mapped I/O. For a system which uses I/O Mapped I/O, there is a requirement for a extra h/w Circuitry.
DMA Direct Memory Access DMA transfers data directly from the drive to memory w/out involving the CPU.
it is a device to transfer the data directly between io device and memory without through the cpu so it performs a high-speed data transfer between memory and io device