Page 129 - DCAP210_INTRODUCTION__TO_MICROPROCESSORS

Unit 8: Interfacing I/O Devices

Notes
Questions:
1. Explain working of Touch tablet.

2. What are the basic problems in Touch tablet?

8.5 Summary

• GUIs can be used in computers, hand-held devices such as MP3 players, portable media
players or gaming devices, household appliances and office equipment.
• Facility type labels and V/C (volume delay) curves for each facility type from the user’s link
file are set in this worksheet.

• Highway network data describe network nodes and links.
• Memory-mapped I/O uses the same address bus to address both memory and I/O devices -
the memory and registers of the I/O devices are mapped to address values.
8.6 Keywords

• ACM(Alternatives comparison module): The alternatives comparison module (ACM)
calculates user benefits resulting from the ITS deployments.
• DMA(Direct memory access):Direct memory access is a feature of modern computers and
microprocessors that allows certain hardware subsystems within the computer to access system
memory for reading and/or writing independently of the central processing unit (CPU).
• MMIO (Memory-mapped I/O): Memory-mapped I/O is an I/O scheme where the device’s
own on-board memory is mapped into the processor’s address space. Data to be written to
the device is copied by the driver to the device memory, and data read in by the device is
available in the shared memory for copying back into the system memory.
• TDM(Travel Demand Model):Travel demand modeling is the utilization of computer software
package to replicate to the real world transportation system around us(road traffic control
devices etc).

1. How to interface 8085 I/O without using interfacing devices?

2. Explain the different types of file with the help of example.

8.7 Self-Assessment Questions

1. Memory mapped IO uses a portion of ........................... to handle IO requests.

(a) RAM (b) ROM
(c) DRAM (d) SRAM
2. The principle function of memory interfacing is not to enable the microprocessor to read
or write into a register of the memory chip.

(a) True (b) False
3. In I/O mapped I/O; I/O devices are handled distinctly by the ........................... .
(a) Monitor (b) Pointer
(c) CU (d) CPU

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