Types of microprocessor

Transcription

1 Types of microprocessor Depending on register 1. Accumulator based 2. Register based Based on aplication 1. Bit Slice Processors 2. General purpose CPUs 3. Dedicated/Embedded controllers

2 Accumulator based microprocessors Examples are -Intel s 8085, Motorola s 6809 also called a 1-operand machine Here, one of the operands is assumed to be held a special register called accumulator. although it may have several registers, all arithmetic and logic operations are performed using this register as one of the data source and result is stored back in the accumulator. All the Data transfer are performed through accumulator. For instance, a CPU might have an instruction like: ADD memaddress that adds the value read from the memory location at memaddress to the value from the accumulator, placing the result in the accumulator. The accumulator is not identified in the instruction by a register number; it is implicit in the instruction and no other register can be specified in the instruction.

3 Block diagram of Accumulator based microprocessors

4 The general-purpose register based microprocessors Examples are -Intel s 8086/386, Motorola s 68000/020 Also called 2-operand or 3-operand machines. These processors have a set of general purpose registers which can be used to hold data, memory addresses or the results of an arithmetic or logic operations for indefinite amount of time and are capable of manipulating data by shift or rotate operations. The number and size of these registers vary from processor to processor Some registers are general purpose while others are earmarked with some functions. Typical dedicated registers include, a. Program Counter (PC) b. Instruction Register (IR) c. Status Register or Flag Register d. Stack Pointer (SP)

5 Block diagram of Register based microprocessors

6 Difference between Accumulator and register based MP Accumulator based MP 1.All operands are held in accumulator. 2.Result after arithmetic and logic operation stored in the accumulator. 3.One address instructions are very predominate in this organization. 4.8-bit mp is usually accumulator based. 5.Lower speed. Register based MP 1.Register is used to hold memory and data. 2.Stored in the register. 3.The number size types of register vary from one mp to another bit and 32-bit usually register based. 5.Higher speed.

7 Difference between Accumulator and register based MP Accumulator based MP Register based MP 6.Data transfer are performed via accumulator. 7. Are made by NMOS technique. 6.Via register. 7. Are Made by HMOS technique 8.Example-intel 8085 Motorola Example intel Motorola-68020,68030

8 Bit slicing concept Bit slicing is a technique for constructing a processor from modules of smaller bit width. Each of these components processes one bit field or "slice" of an operand. The grouped processing components would then have the capability to process the chosen full wordlength of a particular software design.

9 Bit slice processor In a bit-sliced processor, each module contains an ALU (arithmetic-logic unit) usually capable of handling a 4-bit field. By combining two or more identical modules, it is possible to build a processor that can handle any multiple of this value, such as 8 bits, 12 bits, 16 bits, 20 bits, and so on. Examples of bit-slice microprocessor modules can be seen in the Intel 3000 family, the AMD Am2900 family, the National Semiconductor IMP-16 and IMP-8 family, and the

10 Block diagram of bit slice microprocessors Case Study: Intel Processors CMOS VLSI Design Slide 10

11 Dedicated/Embedded Controllers Embedded systems are systems that are dedicated to perform specific functions. They differ from conventional computer systems in that they are not required to be general purpose. Microcontrollers are embedded controllers. Case Study: Intel Processors CMOS VLSI Design Slide 11

12 MICROCONTROLLER Microcontroller (MCU) Integrated electronic computing device that includes three major components on a single integrated circuit chip Microprocessor (MPU) Memory(RAM and ROM) I/O (Input/Output) ports Support Devices Timers A/D converter Serial I/O Common communication lines System Bus Having the complete controller on a single chip allows the hardware design to be simple. Microcontrollers are used increasingly in products as varied as industrial applications, home appliances, and toys.

13 BLOCK DIAGRAM OF MICROCONTROLLER

14 Microcontroller vs. Microprocessors 1. CPU for Computers 2. No RAM, ROM, I/O on CPU chip itself 3. Example:Intel s x86, Motorola s 680x0 1. A smaller computer 2. On-chip RAM, ROM, I/O ports Example:Motorola s 6811, Intel s 8051, Zilog s Z8 and PIC

15 Microcontroller vs. Microprocessors Microprocessor 1. CPU is stand-alone, RAM, ROM, I/O, timer are separate 2. designer can decide on the amount of ROM, RAM and I/O ports. 3. general-purpose Microcontroller 1. CPU, RAM, ROM, I/O and timer are all on a single chip 2. fix amount of on-chip ROM, RAM, I/O ports 3. single-purpose