๐๐ต๐ฎ๐ฝ๐๐ฒ๐ฟ ๐ญ๐ญ: Basic I/O Interface Flashcards
(80 cards)
o transfers information to an I/O device
- OUT
o read information from an I/O device
- IN
o 8-bit form (p8)
- fixed address
o 16 bit I/O address
- Variable address
o the I/O address
- Port number
- ISA
o industry standard architecture
o most common I/O transfer technique used in the Intel microprocessor-based system
- isolated I/O
o does not use the IN, INS, OUT, or OUTS instructions
- Memory-Mapped I/O
o uses any instruction that transfers data between the microprocessor and memory
- Memory-Mapped I/O
o Three-state buffers are used to construct the 8-bit input port
- Basic Input Interface
o receives data from the microprocessor and usually must hold it for some external device.
- Basic Output Interface
o Also called polling
- Handshaking
o synchronizes the I/O device with the microprocessor
- Handshaking
o Are TTL and compatible, and therefore can be connected to the microprocessor and its interfacing components, or they are switch-based
- Input Devices
o are far more diverse than input devices, but many are interfaced in a uniform manner
- Output Devices
o programmable peripheral interface
- PPI
o very popular, low-cost interfacing component found in many applications
- PPI
o can interface any TTL-compatible I/O device to the microprocessor
- 82C55
o have replaced LED displays in many applications
- LCD
o a digital motor because it is moved in discrete steps as it traverses through 360ยฐ
- stepper motor
o This allows external data to be stored into the port until the microprocessor is ready to retrieve it
- Mode 1 Strobed Input
o loads data into the port latch, which holds the information until it is input to the microprocessor via the IN instruction
- STB
- STB
o Strobe
o an output indicating that the input latch contains information
- IBF