A/D and D/A Converter Interfacing with 8085
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (f) A/D and D/A Converter Interfacing with 8085
Fig. 13.3.1 shows the interfacing of DAC 0808 with microprocessor 8085. Here, programmable peripheral interface, 8255 is used as parallel port to send the digital data to DAC.
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (f) A/D and D/A Converter Interfacing with 8085
The IC 1408 consists of a reference current amplifier, an R/2R ladder and eight high speed current switches. It has eight input data lines A1 (MSB) through A8 (LSB) which control the positions of current switches.
A/D and D/A Converter Interfacing with 8085
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (f) A/D and D/A Converter Interfacing with 8085
Review Questions : 1. What is digital to analog converter? 2. Draw the 3-bit digital to analog converter block and plot it's analog output.
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (f) A/D and D/A Converter Interfacing with 8085
Microprocessors and Microcontrollers: Unit IV: (f) A/D and D/A Converter Interfacing with 8085 : Contents
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279 : Two Marks Questions with Answers, University Questions with Answers (Long Answered Questions)
Keyboard and Display Controller - 8279
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
In this section we will discuss many useful applications with different modes of keyboard and display interfacing. In addition to this we are going to see the software requirement to control the interfacing circuits.
Keyboard and Display Controller - 8279
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
Review Question : 1. Draw and explain the interfacing of 8279 with 8085.
Keyboard and Display Controller - 8279
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
In the last sections we have seen various operating modes of 8279. To program 8279 in the desired mode it provides eight command words.
Input and Display
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
Review Questions 1. What do you mean by encoded scan and decoded scan ? 2. Explain the input modes provided by 8279. 3. Explain the terms 2-key lockout and N-key rollover. 4. Why maximum size of keyboard matrix is 8 × 8 = 64, when interfaced with 8279 ? 5. Explain the display modes provided by 8279. 6. Explain the working of 8279 as a keyboard/display controller and explain its command registers
Keyboard and Display Controller - 8279
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
It consists of four main sections : • CPU interface and control section • Scan section • Keyboard section • Display section
CPU Interface , Keyboard and Display Data
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
Fig. 12.4.1 shows functional and pin diagram of 8279. It is a 40 pin device and looking at Fig. 12.4.1 (a) we can see that these pins are divided in four functional groups :
Microprocessors and Microcontrollers
Subject and UNIT: Microprocessors and Microcontrollers: Unit IV: (e) Keyboard and Display Controller - 8279
IC 8279 provides a scanned interface to a 64-contact key matrix, with two more keys CONTROL and SHIFT.