1. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 1 Lecture 5

2. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 2 Last Lecture Logical Partitions of MS-DOS Disk

3. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 3 Today's Lecture Introduction to Intel 8086 microprocessor Intel 8086 CPU Architecture

4. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 4 Intel 8086 Microprocessor Key Features: Released by Intel in 1978 Produced from 1978 to 1990s A 16-bit microprocessor chip. Max. CPU clock rate : 5 MHz to 10 MHz Instruction set: x86-16 Package: 40 pin DIP The 8086 gave rise to the x86 architecture of Intel's future processors. Common manufacturer(s): Intel, AMD, NEC, Fujitsu, Harris (Intersil), OKI, Siemens AG, Texas Instruments, Mitsubishi. The Intel 8088, released in 1979, was a slightly modified chip with an external 8-bit data bus and is notable as the processor used in the original IBM PC.Intel 8088data busIBM PC Fig1:Intel 8086 Microprocessor

5. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 5 8086 CPU Chip Fig1: 8086 CPU Chip in DIP Package Fig2: CPU Chip

6. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 6 Intel 8086 architecture The architecture was defined by Stephen P. Morse with some help and assistance by Bruce Ravenel (the architect of the 8087) in refining the final revisions. Logic designer Jim McKevitt and John Bayliss were the lead engineers of the hardware-level development team and William Pohlman the manager for the project.Stephen P. Morse The legacy of the 8086 is enduring in the basic instruction set of today's personal computers and servers; the 8086 also lent its last two digits to later extended versions of the design, such as the Intel 286 and the Intel 386, all of which eventually became known as the x86 family.Intel 286Intel 386x86

7. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 7 Intel 8086 Process Technology It was implemented using depletion-load nMOS circuitry with approximately 20,000 active transistors (29,000 counting all ROM and PLA sites).transistorsROMPLA It was soon moved to a new refined nMOS manufacturing process called HMOS (for High performance MOS) that Intel originally developed for manufacturing of fast static RAM products.HMOSstatic RAM This was followed by HMOS-II, HMOS-III versions, and, eventually, a fully static CMOS version for battery-powered devices, manufactured using Intel's CHMOS processes.CMOS CHMOS The original chip measured 33 mm² (assume a square of side length=0.57cm) and minimum feature size was 3.2 μm.

8. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 8 Why Choose the Intel 8086? There is need to study a microprocessor. How it works, what is its architecture, what is its instruction set architecture, how it is programmed, how it is interfaced with other devices etc. etc. 8086 is first x86 microprocessor. The term x86 refers to a family of instruction set architectures based on the Intel 8086 CPU. The 8086 was launched in 1978 as a fully 16- bit extension of Intel's early 8-bit based microprocessors and also introduced segmentation to overcome the 16-bit addressing barrier of earlier chips. The term x86 derived from the fact that early successors to the 8086 also had names ending in "86". Many additions and extensions have been added to the x86 instruction set over the years, almost consistently with full backward compatibility.The architecture has been implemented in processors from Intel, Cyrix, AMD, VIA, and many others.instruction set architecturesIntel 8086CPUsegmentationbackward compatibilityIntelCyrixAMDVIA The PC market which uses Intel based devices takes up some 60% of the total microprocessor market! The other main processor used by industry is the Motorola 68000 family of microprocessors.

9. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 9 Current x86 processors http://en.wikipedia.org/wiki/8086 x86-32: EP80579 · Intel CE · Atom EP80579Intel CEAtom x86-64: Atom (some) · Celeron · Pentium (Dual-Core) · Core (i3 · i5 · i7) · XeonAtom (some)Celeron PentiumDual-CoreCorei3i5i7Xeon Other: IOP · ItaniumIOPItanium x86 Assemblers: A86/A386 · FASM · GAS · HLA · MASM · NASM · TASM · WASM · YASMA86/A386FASMGAS HLAMASMNASMTASMWASM YASM http://en.wikipedia.org/wiki/X86_architecture

10. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 10 8086 kit Key features of this trainer kit are such as: 8086/8088 CPU operating at 2.5/5 MHz. 16 KB RAM with Battery backup expandable upto 256 KB. 16 KB powerful monitor EPROM. 24 I/O lines using 8255. 16 bit Timer/Counter using 8253. RS-232C Interface using 8251. 8259 Interrupt Controller. 27 Series EPROM Programmer. Printer Interface [Optional]. These kits are prepared and supplied by many suppliers in India also for training and education purpose. Fig: 8086 kit

11. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 11 http://www.flite.co.uk/the-flite-8086-an-introduction.htm http://www.flite.co.uk/flite-flt-86-8086-training-system.htm System Overview The 8086 is probably the most commonly used 16- bit microprocessor of all time, with the upwardly compatible families of microprocessors developed from it now at the heart of the virtually all personal computers. This makes the 8086 the number one choice as a platform for teaching microprocessor principles on many computer science courses. Fig1: 8086 kit Fig2 The FLT86 is a well established training system for the 8086 CPU still being manufactured by Flite Electronics International Limited in Southampton, England.

12. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 12 8086 microprocessor 16 bit- microprocessor ? 16-bits data bus? Microprocessor 8086 Data Bus Control signals Add Bus Address Bus – 20 lines – A 19 – A 0 Data Bus – 16 lines – D 15 – D 0

13. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 13 20 bits address bus? It can address any one of 1,048,576 (=2 20 ) memory locations/addresses. Each memory location is one byte wide. To store a word of 16 bit 2 memory locations are required. If the first byte of the word is at even address 8086 can read the entire word in one operation. If the first byte of the word is at an odd address, the 8086 will read the first byte with one bus operation and the second byte with another bus operation. 1,048,576 memory locations=1MBytes A 19 ……………A 0 0……………….0 00000H 1……………….1 FFFFFH Memory Address Space 00000H FFFFFH

14. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 14 8086 INTERNAL ARCHITECTURE Fig: 8086 Internal block diagram. 2 units are: 1. BIU 2. EU

15. 19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING 15 BIU and EU BIU (bus interface unit) sends out addresses, fetches instructions from memory, reads data from ports and memory, and writes data to ports and memory. In other words, the BIU handles all transfers of data and addresses on the buses for the execution unit. EU (execution unit) of the 8086 tells the BIU where to fetch instructions or data from, decodes instructions, and executes instructions.