1. Micro-controller or embedded controller
Ceg3430 Chapter 2 Robot 2
Micro-controller or
embedded controller
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2. Robot2: Embedded controller
Content
1. Introduce the family
2. General description of the 8031 processor
3. Memory Interface
4. Parallel port interface
5. Serial Interface
6. Interrupt
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3. Robot2: Embedded controller
References
Intel’s database
Philips’ database
Paulmon, a freeware
On Basic52 by Jan Axelson
Flash ROM based 89C51
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4. A simple micro-controller (e.g. 8048) has
CPU (Central Processing Unit)
Some internal Ram (~1K-byte) and a few (4~8) kilobytes of ROM for holding programs.
Parallel input/output bus so that it can communicate with the outside world.
Be able to take hardware interrupt.
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5. Additional feature of a micro-controller (8031)
Serial input/output so that it can make more distant communications with other computers.
Timers for counting or generating exact timing signals for control purposes.
Power down circuit to keep the internal data even the main power is cut off.
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6. 1.Introduce the Intel 8051 family: 8032/8051/8052
Features:
on chip RAM
(8x31=>128 bytes; 8x51=>256 bytes),
on chip ROM or simple memory interface
on chip timer(8xx1=>2 timers, 8xx2=>3 timers),
on chip interrupt support
Serial (UART), parallel port interface
new products support up to 33MHz clock rate.
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7. Robot2: Embedded controller
8031 family
All have 128 bytes RAM, 2 timers, 32-bit parallel IO, serial IO, 5 interrupt sources
8031 ROM-less ; use external ROM for program
8051 4K-byte ROM
8751 4K-byte UV-EPROM (ultra-violet erasable, re-programmable)
8951 8K-byte (Electrical erasable, re- programmable)
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8. Robot2: Embedded controller
8031 family
All have 128 bytes RAM, 2 timers, 32-bit parallel IO, serial IO, 5 interrupt sources
8031 ROM-less ; K-byte ROM
8751 4K-byte UV-EPROM (ultra-violet erasable, re- programmable)
8951 8K-byte (Electrical erasable, reprogrammable)
Philips extended Architecture (16-bit with AD converter)
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9. Robot2: Embedded controller
Philips’ 80C bit extended architecture (XA) for industrial control
The XA-C3,
supports the full Controller Area Network (CAN) 2.0B. It supports both 11-bit and 29-bit identifiers (ID) at up to 1Mbit/s data rate. It
The XA-S3,
8-channel 8-bit ADC (4.6ms conversion)
16 M-byte (24 bit) addressing
I²C-bus serial I/O port
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10. 2. General description of 8051
8/16/32 Kbyte On-Chip ROM/EPROM program memory
256 x 8-bit RAM
32 Programmable I/O Lines
Three16-Bit Timer/Counters
7 Interrupt Sources
Quick-Pulse EPROM Programming (8751 contains 4Kbyte UV-EPROM)
Programmable Serial Port
32k+32K External Program Memory Space
32K+32k External Data Memory Space
IDLE and POWER DOWN Modes
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11. Robot2: Embedded controller
8XC51FX
pin
assignment
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12. Memory Addressing for the 8051 family
Memory space
128 bytes internal RAM space
address 0-7F (hex) internal data ram,
80-FF internal data and special function registers SFR overlapped addressed by indirect and direct mode resp.
64K program space includes
The lower 4K( or more depends on specific device) on chip ROM/EPROM (if exist)
The rest is external memory
64K external data memory
External interface uses pins: /ALE,/PSEN, IO_PORTS.
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FFFF
32k
SFR=
Special
Function
Register
0FFF
SFR
32k
Program Latch Enable
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15. Robot2: Embedded controller
Special Function Registers at internal RAM address FF hex
Accumulator
Interrupt
priority
Stack pointer
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16. Robot2: Embedded controller
Important Pins
Reset
ALE: Address Latch Enable, to latch address outputs at Port0 and Port2
PSEN: Program Store Enable
Port 0
port 1
port 2
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Power up and after
First let us look at what the 8031 system will do after reset.
Power-up or reset. first instruction from 0000H
A simple startup assembly segment is as follows:
1 Org 0 ;after reset
2 ljmp start ; long jump to start at line
3 Org 30h ; arbitrary, but addr.
4 start: mov sp,30h-1 ; set stack point at 30h
Question: Guess why sp = 30h-1 not 30h?
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External program ROM interface
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Address
Latch
Enable
Program
Store
Enable
A0-A15 : 16 bit = 64K-byte address
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To connect more memory
Use 138 and A12 to do address decoding
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3. Parallel interface 8255
Treated as memory location at E000H
Read/write registers as memory data access
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4. Serial Interface
SM0 SM1 Mode serial Baud rate
0 0 0 F.osc./12 (8-bit)
0 1 1 depends on Timer 1
1 0 2 F.osc./64 or F.osc./32
1 1 3 Depends on Timer 1
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32. 5. five sources of interrupt
TF0 Timer0, Start address: 0003H
TF1 Timer1 Start address: 000BH
INT0 External0 (from external pin /INT0) Start address: 0013H
INT1 External1 (from external pin /INT1) Start address: 001BH
Serial IO interrupt Start address: 0023H
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