may mego kana
yes because when you see the telitobies you get a free ticket to watch barney and his friends its so awsme
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.
disadvantages of interrupt
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.
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.
Peripheral-Mapped IO is IO that is selected when the IO/M- line is high.
arithmetic and logic operation can directly perform with I/O data all i/o devices are treated as memory use 16 bit address
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
IO/M- is used in the 8085 to qualify IO operations vs memory operations.
To read and write to I/O