MPLAB C Compiler for PIC24 MCUs and dsPIC DSCs ... - Microchip

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16-Bit C Compiler User’s Guide 7.7.3 Additional Sources of Information Section 5 of the “dsPIC30F Family Reference Manual” (DS70046) has an excellent discussion on using the Flash program memory and EE data memory provided on the dsPIC DSC devices. This section also has information on run-time programming of both program memory and EE data memory. DS51284H-page 98 © 2008 Microchip Technology Inc.
8.1 INTRODUCTION 8.2 HIGHLIGHTS MPLAB ® C COMPILER FOR PIC24 MCUs AND dsPIC ® DSCs USER’S GUIDE Chapter 8. Interrupts Interrupt processing is an important aspect of most microcontroller applications. Interrupts may be used to synchronize software operations with events that occur in real time. When interrupts occur, the normal flow of software execution is suspended and special functions are invoked to process the event. At the completion of interrupt processing, previous context information is restored and normal execution resumes. The 16-bit devices support multiple interrupts from both internal and external sources. In addition, the devices allow high-priority interrupts to override any low priority interrupts that may be in progress. The compiler provides full support for interrupt processing in C or inline assembly code. This chapter presents an overview of interrupt processing. Items discussed in this chapter are: • Writing an Interrupt Service Routine – You can designate one or more C functions as Interrupt Service Routines (ISR’s) to be invoked by the occurrence of an interrupt. For best performance in general, place lengthy calculations or operations that require library calls in the main application. This strategy optimizes performance and minimizes the possibility of losing information when interrupt events occur rapidly. • Writing the Interrupt Vector – The 16-bit devices use interrupt vectors to transfer application control when an interrupt occurs. An interrupt vector is a dedicated location in program memory that specifies the address of an ISR. Applications must contain valid function addresses in these locations to use interrupts. • Interrupt Service Routine Context Saving – To handle returning from an interrupt to code in the same conditional state as before the interrupt, context information from specific registers must be saved. • Latency – The time between when an interrupt is called and when the first ISR instruction is executed is the latency of the interrupt. • Nesting Interrupts – The compiler supports nested interrupts. • Enabling/Disabling Interrupts – Enabling and disabling interrupt sources occurs at two levels: globally and individually. • Sharing Memory Between Interrupt Service Routines and Mainline Code – How to mitigate potential hazards when this technique is used. • PSV Usage with Interrupt Service Routines – Using ISRs with managed psv pointers and CodeGuard Security psv constant sections. © 2008 Microchip Technology Inc. DS51284H-page 99
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MPLAB ® C COMPILER FOR PIC24 MCUs
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Table of Contents A.5 Identifiers .
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INTRODUCTION MPLAB ® C COMPILER FO
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CONVENTIONS USED IN THIS GUIDE The
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THE MICROCHIP WEB SITE Preface C Re
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1.1 INTRODUCTION 1.2 HIGHLIGHTS MPL
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1.5 COMPILER FEATURE SET Compiler O
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Differences Between 16-Bit Device C
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Using the Compiler on the Command L
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Page 89 and 90: 6.3 PMP POINTERS Additional C Point
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Page 145 and 146: A.24 GETENV A.25 SYSTEM A.26 STRERR
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__builtin_fbcl Built-in Functions A
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__builtin_modsd Argument: dividend
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__builtin_mpy Error Messages An err
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__builtin_mulss Built-in Functions
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__builtin_psvoffset Built-in Functi
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__builtin_subab Built-in Functions
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__builtin_tblwth Built-in Functions
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C.1 INTRODUCTION C.2 ERRORS MPLAB
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Diagnostics ambiguous abbreviation
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Diagnostics cast specifies function
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F Diagnostics ‘identifier’ fail
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Diagnostics initializer for static
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Diagnostics invalid use of undefine
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N Diagnostics negative width in bit
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R Diagnostics redeclaration of ‘i
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Diagnostics symbol ‘symbol’ not
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Diagnostics void expression between
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Diagnostics anonymous union declare
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Diagnostics comparison between sign
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duplicate ‘const’ The ‘const
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Diagnostics function might be possi
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Diagnostics ‘identifier’ is nar
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Diagnostics library function ‘ide
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P Diagnostics parameter has incompl
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Diagnostics shift count >= width of
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Diagnostics too many arguments for
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V Diagnostics __VA_ARGS__ can only
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MPLAB C Compiler for PIC18 MCUs vs.
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E.1 INTRODUCTION E.2 HIGHLIGHTS MPL
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G.1 PREAMBLE MPLAB ® C COMPILER FO
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G.3 VERBATIM COPYING G.4 COPYING IN
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GNU Free Documentation License incl
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Glossary File Registers On-chip dat
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Glossary Machine Language A set of
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Glossary Stack, Software Memory use
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Symbols __builtin_add..............
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Peephole Optimization..............
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-Wsequence-point...................
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