RC RESET Context ● You are developing an embedded application using one or more members of the 8051 family of microcontrollers. ● You are designing an appropriate hardware foundation for your application. Problem How do you create a low-cost reset circuit for your 8051 microcontroller? Background As discussed in the introduction to this chapter, the […]
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CRYSTAL OSCILLATOR
CRYSTAL OSCILLATOR Context ● You are developing an embedded application using one or more members of the 8051 family of microcontrollers. ● You are designing an appropriate hardware foundation for your application. Problem When and how should you use a quartz crystal to create an oscillator for use with members of the 8051 family of […]
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Reset hardware
Introduction The process of starting any microcontroller is a non-trivial one. The underlying hard- ware is complex and a small, manufacturer-defined ‘reset routine’ must be run to place this hardware into an appropriate state before it can begin executing the user program. Running this reset routine takes time and requires that the microcontroller’s oscillator is […]
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CERAMIC RESONATOR
CERAMIC RESONATOR Context ● You are developing an embedded application using one or more members of the 8051 family of microcontrollers. ● You are designing an appropriate hardware foundation for your application. Problem When and how should you use a ceramic resonator with members of the 8051–family microcontrollers? Background A ceramic resonator is, like a […]
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The 8051 microcontroller family
Introduction Early in the life-cycle of most embedded projects, an initial choice of microcontroller must be made. While it may become necessary to change the microcontroller as the project develops, the particular hardware platform that is used will have a substantial impact on many later software and hardware design decisions and development costs can be […]
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The 8051 microcontroller family:EXTENDED 8051
EXTENDED 8051 Context You are developing a microcontroller-based embedded application and have some flexibility in the choice of hardware platform to be used. Problem Should you base your application on an Extended 8051-family microcontroller? Background As we have seen in connection with ST ANDARD 8051 [page 30] and SMALL 8051 [page 41], this long-lived microcontroller […]
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The 8051 microcontroller family:SMALL 8051
SMALL 8051 Context You are developing a microcontroller-based embedded application and have some flexibility in the choice of hardware platform to be used. Problem Should you base your application on a Small 8051-family microcontroller? Background The desktop microprocessor market is characterized by constant demands for increased power. As a result, processors become obsolete after two […]
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Oscillator hardware
Introduction All digital computer systems are driven by some form of oscillator circuit. This circuit is the ‘heartbeat’ of the system and is crucial to correct operation. For example, if the oscillator fails, the system will not function at all; if the oscillator runs irregularly, any timing calculations performed by the system will be inaccurate. […]
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Designing embedded systems:Conclusions
Conclusions In this second brief introductory chapter, we have argued that developers of embedded applications can benefit from pattern-driven design techniques not least because many embedded projects require the developer to have both knowledge of software design and from a range of related technical and engineering fields. Four points should be made as we conclude […]
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Designing embedded systems using patterns:Patterns
Patterns We can sum up the conclusions from these two examples by saying that – for those developers with experience of control system design, or the use of LED displays – the tasks are straightforward: however, for those without such experience, even the small- est of decisions can have unexpected repercussions. Unfortunately, the standard design […]
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