DSP/BIOS Run-time Support Library | Texas Instruments TMS320 DSP

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TI C-Language Run-Time Support Library

Recall that only a subset of the DSP/BIOS and the TI C run-time support library functions are allowed to be referenced from an eXpressDSP-compliant algorithm.

B.1 TI C-Language Run-Time Support Library

In the future, this list of allowable APIs will grow to include a rich set of DSP math function calls; e.g., functions for computing a DCT, FFT, dot product, etc.

The following table summarizes the TI C-Language Run-time Support Library functions that may be referenced by eXpressDSP-compliant algorithms.

Allowed or
Disallowed	Category	Typical Functions in Category
allowed	String functions	strcpy, strchr, etc
allowed	Memory-moving functions	memcpy, memmove, memset, etc.
allowed	Integer math support	_divi, _divu, _remi, _remu, etc.
allowed	Floating point support	_addf, _subf, _mpyf, _divf, _addd, _subd, _mpyd, _divd,
		log10, cosh, etc.
allowed	Conversion functions	atoi, ftoi, itof, etc.
disallowed	Heap management functions	malloc, free, realloc, alloc, …
disallowed	I/O functions	printf, open, read, write, etc
disallowed	misc. non-reentrant functions	printf, sprintf, ctime, etc.

Notes

(1)

(2)

(2)

(2)(3)

(2)

(4)

(5)

(4)(6)

(1)Exceptions: strtok is not reentrant, and strdup allocates memory with malloc.

(2)Some of these are issued by the compiler automatically for certain C operators.

(3)The errno paradigm is not reentrant. Thus, errno must not be used by eXpressDSP-compliant algorithms.

(4)Algorithms must not allocate memory.

(5)Algorithms are not allowed to perform I/O.

(6)Algorithms must be reentrant and must, therefore, only reference reentrant functions.

B.2 DSP/BIOS Run-time Support Library

The HWI module'sHWI disable, HWI enable, and HWI restore are the only allowed DSP/BIOS functions. These operations can be used to create critical sections within an algorithm and provide a processor-independent way of controlling preemption when used in a DSP/BIOS framework.

82

Core Run-Time APIs

SPRU352G –June 2005 –Revised February 2007

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Image 82

Texas Instruments TMS320 DSP manual TI C-Language Run-Time Support Library, DSP/BIOS Run-time Support Library

Contents

Users Guide Rules and Guidelines Submit Documentation Feedback Contents Use of the DMA Resource Urls List of Figures Intended Audience Read This FirstDocument Overview Rule n Related DocumentationText Conventions Guideline n Overview Scope of the Standard Rules for TMS320C5x Rules for TMS320C6x Rules and Guidelines Requirements of the Standard Goals of the Standard Intentional Omissions System Architecture Frameworks Algorithms Core Run-Time Support General Programming Guidelines Threads Use of C LanguageThreads and Reentrancy Rule Preemptive vs. Non-Preemptive Multitasking Reentrancy Example Data Memory Data Memory Memory Spaces Scratch versus Persistent Scratch vs Persistent Memory Allocation Algorithm versus Application Guideline ROM-ability Program MemorySection Name Purpose Use of Peripherals Use of Peripherals Algorithm Component Model Interfaces and Modules Algorithms Packaging Interfaces and Modules Implementation Fir.h External Identifiers Module Initialization and Finalization Naming ConventionsModule Instance Objects Design-Time Object Creation Run-Time Object Creation and Deletion Module Configuration Example Module Multiple Interface Support Element Interface InheritanceSummary Description Required Algorithms Algorithms Packaging Object Code Header Files Debug Verses Release Moduleversvendorvariant.1arch Algorithm Performance Characterization Data Memory Program Memory Interrupt Latency Execution Time External Heap MemorySize Stack Memory Static Local and Global Data Memory Data Bss Object files Size Mips Is Not Enough Interrupt LatencyExecution Time Operation Execution Time Model Execution Timeline for Two Periodic Tasks 198000 Process59000 198000 Submit Documentation Feedback DSP-Specific Guidelines CPU Register Types Register Types Endian Byte Ordering Use of Floating PointTMS320C6xxx Rules and Guidelines Data Models Register Use Type Register ConventionsStatus Register CSR Field Use Type TMS320C54xx Rules and Guidelines Interrupt LatencyProgram Models TMS320C54xx Rules and Guidelines ST0 Field Name Use Type Status RegistersST1 Field Name Use Type Stack Architecture TMS320C55x Rules and GuidelinesPmst Field Name Use Type Relocatability Example SSP ST2 Field Name Use Type Status BitsST3 Field Name Use Type Homy TMS320C24xx Guidelines General TMS320C28x Rules and Guidelines TMS320C28x Rules and Guidelines XAR0 M0M1MAP Use of the DMA Resource Submitting DMA Transfer Requests Overview Algorithm and Framework Requirements for the Use of the DMA Resource Logical Channel Data Transfer Properties Data Transfer Synchronization DMA Guideline Abstract InterfaceDMA Rule Data Transfers bytes Frequency Resource CharacterizationAverage Maximum Runtime APIs Strong Ordering of DMA Transfer Requests Submitting DMA Transfer Requests Device Independent DMA Optimization Guideline Cache Coherency Issues for Algorithm Producers 13 C6xxx Specific DMA Rules and Guidelines Supporting Packed/Burst Mode DMA Transfers 14 C55x Specific DMA Rules and Guidelines Inter-Algorithm Synchronization Minimizing Logical Channel Reconfiguration OverheadAddressing Automatic Endianism Conversion Issues Non-Preemptive System Preemptive System Algorithm B Algorithm a Inter-Algorithm Synchronization Appendix a General Rules Performance Characterization Rules DMA Rules General Guidelines DMA Guidelines Submit Documentation Feedback DSP/BIOS Run-time Support Library Core Run-Time APIs DSP/BIOS Run-time Support Library TI C-Language Run-Time Support Library Bibliography Books Submit Documentation Feedback Glossary Glossary of Terms Glossary of Terms Glossary of Terms Important Notice