EDNE November 2012 - (Page 31)

LITTLE-ENDIAN PROCESSOR GENERAL-PURPOSE REGISTER BIG-ENDIAN ASIC GENERAL-PURPOSE REGISTERS REGISTER ADDRESS 0 BB AA International Exhibition and Conference AA BB 1 for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management Nuremberg, 14 – 16 May 2013 figure 1 if the bus does not support big-endian access, a direct access would put the data in the wrong register in the asic. LITTLE-ENDIAN PROCESSOR GENERAL-PURPOSE REGISTER EDN King Renesas Fig 1.eps BIG-ENDIAN ASIC GENERAL-PURPOSE REGISTER REGISTER DIANE ADDRESS 0 AA BB Powerful? …then you are right here! AA BB 1 figure 2 if the chosen processor has big-endian programmability on the external bus, the hardware handles all “byte reordering,” including the proper byte decode for byte accesses. D7 PARITY 0×D5= 1 1 0 C_DATA 1 0 1 0 D0 1 LITTLE ENDIAN EDN King Renesas Fig 2.eps DIANE D7 C_DATA 0×D5= 1 1 0 1 0 1 D0 PARITY 0 1 BIG ENDIAN The marketplace for developers and innovators. Future starts here! figure 3 as soon as code that is not portable is moved to a big-endian processor, it fails to operate as expected; this “incompatibility” is easy to see in the figure, which show the bits in memory with a value. EDN King Renesas Fig 3.eps DIANE www.edn-europe.com NOVEMBER 2012 | EDN EuropE 31 http://www.mesago.de/en/PCIM/home.htm http://www.edn-europe.com

Table of Contents for the Digital Edition of EDNE November 2012

Digi-Key
Cover
Agilent Technologies
Contents
International Rectifier
Microchip
Digi-Key
Masthead
EDN comment
Microchip
Pulse
Analog Devices
Maxim Integrated
Maxim Integrated
Texas Instruments
Silicon Laboratories
Test & Measurement World
FTDI
Digi-Key
Strategies for extending product reliability
Managing the 8- to 32-bit processor migration
PCIM
Pickering Interfaces
Mechatronics in Design
Baker's Best
Digi-Key
Emerson
30 years of DSP
Hirose
Vicor
The nuances of variable-frequency drives
Digi-Key
National Instruments
Volt’s battery-stack manager aids Chevy’s drive
Digi-Key
EDNE
Design Ideas
RS Components
RS Components
RS Components
Product Roundup
Tales from the Cube
RS Components

EDNE November 2012