Module 4 presentation - 2011 Edition by D. G. Meyer...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 2011 Edition by D. G. Meyer Microcontroller-Based Digital System Design Module 4 Embedded System Design Issues Module 4 Module 4 c Desired Outcome: Desired Outcome: An ability to An ability to design and design and implement a (turn implement a (turn-key) microcontroller key) microcontroller-based based embedded system embedded system Part A: Part A: Hardware and Software Development Hardware and Software Development ips ips Tips Tips Part B: Part B: Comparing Alternative Comparing Alternative Microcontrollers for Embedded Applications Microcontrollers for Embedded Applications Microcontroller-Based Digital System Design 2009 Edition by D. G. Meyer Module 4-A Hardware and Software Development Tips Outline Outline c Memory Models c Discussion c Application Code Organization ealing ith Random Behavior c Dealing With Random Behavior c Avoiding Really Stupid Tricks Memory Models - 1 s What are the primary differences between general- purpose processor memory models and embedded processor memory models? h Flat memory model (typically no memory hierarchy or virtual memory) h Limited (fixed, non-infinite) SRAM data space and Flash program space h Non-homogeneous memory types b SRAM read/write (volatile unless battery backup used) b Flash read only (non-volatile in-circuit, sector- erasable and reprogrammable) b EEPROM read mostly (non-volatile in-circuit, byte-erasable and reprogrammable) Memory Models - 2 s How do these differences in memory models influence way in which high-level language code is written? h Dont use too high a level of abstraction b Avoid use of big library routines (e.g., printf) b Avoid dynamic memory allocation void complex data structures b Avoid complex data structures b Avoid recursive constructs b Watch declarations (char, int, long) h Treat C like a macro-assembly language h Remember that floating point support is emulated by lengthy software routines h Remember that using table lookup might be a better approach for transcendental functions (sin, cos, tan, log) than calculation via software emulation Discussion - 1 s What does real time mean (or, what are the key characteristics of a real time system)? h there are mission critical timing constraints (usually tied to input/output data sampling tes and/or data processing overhead) rates and/or data processing overhead) h service latencies are known and fairly tightly bounded h are typically event-driven h require low overhead context switching Discussion - 2 h What does fail safe mean in the context of embedded software (firmware) development? h A f a i l - s a f e o r f a i l - s e c u r e d e v i c e i s o n e t h a t , i n t h e e v e n t o f f a i l u r e , r e s p o n d s i n a w a y t h a t w i l l c a u s e n o h a r m , o r a t l e a s t a m i n i m u m o f h a r m , t o o t h e r h a r m , o r a t l e a s t a m i n i m u m o f h a r m , t o o t h e r...
View Full Document

This note was uploaded on 02/05/2012 for the course ECE 362 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

Page1 / 60

Module 4 presentation - 2011 Edition by D. G. Meyer...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online