10-04-2017, 09:22 PM
elevator implementation using 8086 and 8255
The 8086("eighty eighty-six", also called iAPX 86)is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The Intel 8088, released in 1979, was a slightly modified chip with an external 8-bit data bus (allowing the use of cheaper and fewer supporting ICs[note 1]), and is notable as the processor used in the original IBM PC design, including the widespread version called IBM PC XT.The 8086 gave rise to the x86 architecture which eventually became Intel's most successful line of processors.
The Intel 8255 (or i8255) Programmable Peripheral Interface (PPI) chip is a peripheral chip originally developed for the Intel 8085 microprocessor,and as such is a member of a large array of such chips, known as the MCS-85 Family. This chip was later also used with the Intel 8086 and its descendants. It was later made (cloned) by many other manufacturers. It is made in DIP 40 and PLCC 44 pins encapsulated versions.
AIM:-
To Interface Digital -to-Analog converter to 8086 using 8255 and write Assembly Language Program to generate Square Wave, Ramp Wave, Triangular Wave & Staircase Wave form.
APPARATUS:-
Microprocessor trainer kit, ADC kit, power supply, data cable, CRO etc
THEORY:-
The DAC 0800 is a monolithic 8 bit high speed current output digital to analog converters featuring setting time of 100nSEC. It also features high compliance complementary current outputs to allow differential output voltage of 20 Vp-p with simple resistor load and it can be operated both in unipolar and bipolar mode.
FEATURES:-
Fast setting output current 100nS
Full scale error +/- 1 LSB
Complementary current outputs
easy interface to all microprocessor
Wide power supply range +/- 4.5 to +/- 18V
low power consumption
WORKING:-
When chip select of DAC is enabled then DAC will convert digital input value given through portliness PB0-PB7 to analog value. The analog output from DAC is a current quantity. This current is converted to voltage using OPAMP based current-to-voltage converter. The voltage outputs (+/- 5V for bipolar 0 to 5V for unipolar mode) of OPAMP are connected to CRO to see the wave form.