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Device Performance Optimization
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
125
Figure 6-4. Influence of compiler settings on application performance and code size
NOTE
Data measured using Dhrystone version 2.1 run on a Power Architecture
based powertrain device that uses a standard commercial compiler.
The compiler optimizations do not necessarily have to be applied to the entire application. Analysis of an
application can identify time critical functions that may subsequently be targeted for performance
optimization, without incurring the impact of optimizing the entire application.
There are several other aspects of the compiler and linker that should be considered. In particular, the use
of Small Data Areas (SDAs, sometimes referred to as Special Data Areas) can make a significant
performance improvement. Refer to compiler documentation for usage guidelines on Small Data Areas.
6.4.2
Signal processing extension
To further optimize time critical functions, the Signal Processing Extension Auxiliary Processing Unit
(SPE-APU) may be used. The SPE-APU provides a set of Single Instruction Multiple Data (SIMD)
instructions. These SIMD instructions typically involve performing the same operation on multiple data
elements stored within a single 64-bit register. Through the implementation of SIMD instructions,
including vector multiply and accumulate (MAC) instructions, the SPE APU provides Digital Signal
Processing (DSP) functionality. This can be used to accelerate signal processing routines, such as Finite
Impulse Response (FIR), Infinite Impulse Response (IIR) and Discrete Fourier Transforms (DFT). A more
general benefit of the SPE instruction set is the ability to load/store 64-bits of data in single instruction.
Thus highly load/store intensive functions make good candidates for SPE optimization.
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Performance vs. Code Size
Normali
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ime
Normalized Code Size
Size optimized
Trade-off
Speed optimized
Содержание MPC5644A
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Страница 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Страница 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Страница 130: ...Device Performance Optimization MPC5644A Microcontroller Reference Manual Rev 6 130 Freescale Semiconductor...
Страница 204: ...Multi Layer AHB Crossbar Switch XBAR MPC5644A Microcontroller Reference Manual Rev 6 204 Freescale Semiconductor...
Страница 212: ...Peripheral Bridge PBRIDGE MPC5644A Microcontroller Reference Manual Rev 6 212 Freescale Semiconductor...
Страница 558: ...System Integration Unit SIU MPC5644A Microcontroller Reference Manual Rev 6 558 Freescale Semiconductor...
Страница 582: ...Frequency modulated phase locked loop FMPLL MPC5644A Microcontroller Reference Manual Rev 6 582 Freescale Semiconductor...
Страница 766: ...Enhanced Time Processing Unit eTPU2 MPC5644A Microcontroller Reference Manual Rev 6 766 Freescale Semiconductor...
Страница 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Страница 1236: ...System Information Module and Trim SIM MPC5644A Microcontroller Reference Manual Rev 6 1236 Freescale Semiconductor...
Страница 1250: ...Cyclic Redundancy Checker CRC Unit MPC5644A Microcontroller Reference Manual Rev 6 1250 Freescale Semiconductor...
Страница 1336: ...Deserial Serial Peripheral Interface DSPI MPC5644A Microcontroller Reference Manual Rev 6 1336 Freescale Semiconductor...
Страница 1388: ...Enhanced Serial Communication Interface ESCI MPC5644A Microcontroller Reference Manual Rev 6 1388 Freescale Semiconductor...
Страница 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...
Страница 1624: ...FlexRay Communication Controller FlexRay MPC5644A Microcontroller Reference Manual Rev 6 1624 Freescale Semiconductor...
Страница 1670: ...JTAG Controller JTAGC MPC5644A Microcontroller Reference Manual Rev 6 1670 Freescale Semiconductor...
Страница 1692: ...Nexus Port Controller NPC MPC5644A Microcontroller Reference Manual Rev 6 1692 Freescale Semiconductor...
Страница 1701: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 Freescale Semiconductor 1701...
Страница 1702: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 1702 Freescale Semiconductor...