1. GENERAL BLOCK DIAGRAM FOR MICROPROCESSOR AND MICROCONTROLLER
11-Jul-19
Micro 8051

2. General-purpose microprocessors
Must add RAM, ROM, I/O ports, and timers externally to make them functional.
Make the system bulkier and much more expensive.
Have the advantage of versatility on the amount of RAM, ROM, and I/O ports.
Microcontroller
The fixed amount of on-chip ROM, RAM, and number of I/O ports makes them ideal for many applications in which cost and space are critical.
In many applications, the space it takes, the power it consumes, and the price per unit are much more critical considerations than the computing power.
11-Jul-19
Micro 8051

3. Microprocessor – Basic concept
ADDRESS BUS 32-bit / 64-bit wide
CONTROL BUS Timing signals, ready signals, interrupts etc
DATA BUS – bidirectional 8-bit / 16-bit / 32-bit / 128-bit
CPU
Contains
ALU data registers and pointer registers
Microprocessor, by-itself, completely useless – must have external peripherals to
Interact with outside world
11-Jul-19
Micro 8051

4. Microprocessor – Basic concept
CONTROL
ADDRESS
DATA
CPU
Contains
ALU data registers and pointer registers
BOOT ROM
Used at startup
Instruction (program) ROM
Transducers
Keyboard Screen UART Parallel interface
etc
Data RAM
commonly implies use as a sensor/detector, any device which converts energy can be considered a transducer.
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Microprocessor, by-itself, completely useless – must have external peripherals to
Interact with outside world
11-Jul-19
Micro 8051

5. Issues with external devices
Many pins
Design time increased – routing issues
Cost increased
board size increased.
Don’t have “flexibility”.
Note: A generic term for any interface logic or protocol that connect two components
(GLUE LOGIC).
11-Jul-19
Micro 8051

6. Microcontroller – Basic concept
ADDRESS
DATA
CPU
Contains
ALU data registers and pointer registers
BOOT ROM
Used at startup
Instruction (program) ROM
Transducers
UART Parallel interface
Etc
Data RAM
Microcontroller – put a limited amount of most commonly used resources
“inside” the chip
11-Jul-19
Micro 8051

7. Advantages of microcontroller
Pin count down
Design time down, Board layout size down
Upgrade path easier – matching between peripherals
Cost down – bulk purchases
Reliability up
Common software / hardware design available from manufacturer
11-Jul-19
Micro 8051

8. Issues Two types of memory Real time environment:
On-chip – fast, easy to access, “almost like a register”, limited amount available
Off-chip – slower
Real time environment:
Event driven – can’t WAIT for a device to become ready, can’t POLL to see if device is ready,
interrupt handling is key
The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations.
A video codec is a device or software that enables video compression and/or decompression for digital video.
11-Jul-19
Micro 8051

9. Microprocessor vs. Microcontroller
CPU, RAM, ROM, I/O and timer are all on a single chip
Fixed amount of on-chip ROM, RAM, I/O ports
For applications in which cost, power and space are critical
Not versatility
Single-purpose (control-oriented)
Low processing power
Low power consumption
Instruction sets mainly focus on control and bit-level operations (CLR C, SETB P1.0 etc.,)
Typically single-cycle/two-stage pipeline.
More number of pins are multifunctioned.
Microprocessor
CPU is stand-alone, RAM, ROM, I/O, timer are separate
Designer can decide on the amount of ROM, RAM and I/O ports.
Expensive
Versatility
General-purpose
High processing power
High power consumption
Instruction sets has one or few bit handling)
Typically deep pipeline (5-20 stages)
Less number of pins are multifunctioned.
versatility 多用途的: any number of applications for PC
11-Jul-19
Micro 8051

10. 11-Jul-19
Micro 8051