The 87LPC767 is a 20-pin single-chip microcontroller; it is intended for low system cost applications, with a low pin count, that demand high integration. This microcontroller has its relations within the Philips low-pin count family. The 87LPC767 is ideal for applications that contain sensors
The applications best suited for 87LPC767 microcontroller is a remote control transmitter unit.
The Features:
- 8 keypad interrupt inputs.
- Programmable port output configuration options: quasibidirectional, open drain, push-pull, input only.
- Two 16-bit counter/timers. Each timer can be configured to toggle a port output upon timer overflow.
- LED drive capability(20 mA) on all port pins.
- Watchdog timer with separate on-chip oscillator, requiring no external components
68HC11 microcontroller
The 68HC11 is a microcontroller made by Motorola, it’s powerful with an 8-bit data, 16-bit address and an instruction set, Timers, RAM EEPROM/OTPROM digital I/O, A/D converter PWM generator, and synchronous and asynchronous communication channels (RS232 and SPI) are built into the 68HC11 microcontroller.
The application best suited for 68HC11 microcontroller is an emergency communicator system application because it
- Records a set of personalised emergency messages.
- Dial customised telephone number(s) when triggered by a pushbutton, monitor, sensors etc.
- Monitor call status and delivers recorded massages.
The Features:
- Power saving STOP and WAIT modes
- Synchronous Serial Peripheral Interface (SPI)
- 8-channel 8-bit Analog-to-digital (A/D) converter
- HCMOS
- EEPROM
- Clock monitor
- Parallel input/output
- Highest priority interrupt
- 16-bit Timer system
Features applied to the emergency communicator system
Low power - operates on battery backup
Noise immunity - operates in surroundings with telephone line and (possibly) radio transmitters
Calibration table -look up values for dial tones, ring back signals, busy signals etc.
User parameters - a list of telephone numbers to call in a case of different emergencies
System configuration – the locality of the emergency message “phrases” in memory
- Analog-to-digital converter
Convert voice input to digital for recording message phrases
- Serial peripheral interface
Transmission of serial ASCII data to an LCD display unit for the user interface
Input capture functions in order to measure the signals on the telephone line to supervise the call status.
Real-time interrupt will display the time since call request
Manage input and output (simple mode)
External memory interface
Minimise power usage when the unit is idle
Whilst the system is in the WAIT mode, the clock monitor will confirm that the correct operations is taking place, and if any errors are detected it can reset the system.
- Highest priority interrupt
IRQ is elevated to the highest priority as this shows a request for an emergency message
80251 microcontrollers
This is first 8051 microcontroller families, and still is one of the most commonly used, these are relatively cheap, encompass decent tools, and also presents a good possibility of upgrading to larger and more capable parts.
Intel is the first company that is responsible for the 8051 family, other companies has taken up the idea and largely produces these microcontrollers, such as Atmel, Dallas Semiconductors, and Philips
The suitable application for 80251 microcontrollers would be a cellular phone application. Because of the features it has which is similar to a cellular phone:
- UART (Universal Asynchronous Receiver Transmitter)
To transfer data, to and from the serial port
To reset processor after a specified interval when activated, and provides a means of gracefully recovering from system problems
To provide a means of interrupt polling and handle real-time interrupt that may occur.
- Power Monitoring and Management
This mode is very useful in terms of reducing power consumption when the processor is idle.
- SPI (Serial Protocol Interface)
This is a protocol for wireless connectivity
- µ Wire (Synchronous Serial Interface)
for interfacing to microcontroller
The Features:
- UART (Universal Asynchronous Receiver Transmitter)
- Watchdog Timer
- SPI (Serial Protocol Interface)
- Interrupt handler
- µ Wire (Synchronous Serial Interface)
- Power Monitoring and Management
- ROM
REFERENCES
University of East London
School of Computing and Technology
Integrated Systems Design
Assignment: Microcontrollers
Submission Date: 24/11/2003
Student: Mohon Miah
Tutor: Mr. J.F.Cox
