80286 MICROPROCESSOR 8.1 Salient Features of 80286 The 80286 is the first member of the family of advanced microprocessors with memory management and protection abilities. The 80286 CPU, with its 24-bit address bus is able to address 16 Mbytes of physical memory. Various versions of 80286 are available that runs on 12.5 MHz , 10 […]
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8086 Microprocessors & Peripherals
RS 232 Serial Communication Standards
8.4 RS 232 Serial Communication Standards In serial I/O, data can be transmitted as either current or voltage. When data is transmitted as voltage, the commonly used standard is known as RS-232C. This standard was developed by Electronic Industries Association (EIA), USA and adopted by IEEE. RS-232 standard proposes a maximum of 25 signals for […]
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NUMERIC DATA PROCESSOR 8087
8.3 NUMERIC DATA PROCESSOR 8087 The numeric data processor is a coprocessor which has been designed to work under the control of the 8086 processor. It offers additional numeric processing capabilities. It is available in 5 MHz, 8 MHz and 10 MHz versions 8086 will perform the opcode fetch cycles and identify the instructions for […]
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SERIAL COMMUNICATION USING 8251
8.2 SERIAL COMMUNICATION USING 8251 8251 is a Universal Synchronous and Asynchronous Receiver and Transmitter compatible with Intel’s processors. This chip converts the parallel data into a serial stream of bits suitable for serial transmission. It is also able to receive a serial stream of bits and convert it into parallel data bytes to be […]
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DMA Controller 8257
DMA Controller 8257 The Direct Memory Access or DMA mode of data transfer is the fastest amongst all the modes of data transfer. In this mode, the device may transfer data directly to/from memory without any interference from the CPU. The device requests the CPU (through a DMA controller) to hold its data, address and […]
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Module7 8086 Microprocessor and Peripherals part4 .
Command Words of 8259A The command words of 8259A are classified in two groups, viz. initialization command words (ICWs) and operation command words (OCWs)Initialization Command Words (ICWs) Before it starts functioning, the 8259A must be initialized by writing two to four command words into the respective command word registers. These are called as initialization command […]
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Module7 8086 Microprocessor and Peripherals part3 .
Operating Modes of 8253 Each of the three counters of 8253 can be operated in one of the following six modes of operation. 1. Mode0 (Interrupt on terminal count) 2. Model (Programmable monoshot) 3. Mode2 (Rate generator) 4. Mode3 (Square wave generator) 5.Mode4 (Software Triggered robe) 6.Mode5 (Hardware triggerred strobe) In this section, we will […]
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Module7 8086 Microprocessor and Peripherals part2 .
Display Modes There are various options of data display The first one is known as left entry mode or type writer mode. Since in a type writer the first character typed appears at the left-most position, while the subsequent characters appears successively to the right of the first one. The other display format is known […]
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Module7 8086 Microprocessor and Peripherals part1 .
8279 Programmable Keyboard/Display Controller and Interfacing The Keyboard/Display Controller 8279 Intel’s 8279 is a general purpose Keyboard Display controller that simultaneously drives the display of a system and interfaces a Keyboard with the CPU. The Keyboard Display interface scans the Keyboard to identify if any key has been pressed and sends the code of the […]
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Module6 8086 Microprocessor and Peripherals part3 .
Parallel Printer Interface: For the most common printer such as the IBM PC printer, the Epson dot matrix printers and the Panasonic dot matrix printers, data to be printed is sent to the printer as ASCII characters on eight parallel lines. The printer receives the characters to be printed and stores them in an internal […]
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