Lpc2000

Pieter Verstraelen ha scritto:

>Hello group,
>
>we will be using the LPC2210 in Big Endian mode to interface to an Epson
>S1D13A05.  
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Hmmm... ARM7 core is set to little endian by hardware for Philips cores. 
This means that if you have to interface a 16 bit wide memory mapped 
chip could be best to interface high byte address to low byte address 
and viceversa because adjust byte words by software has an overhead.

>In Little Endian you simply start at D0 and use up to D7, D15
>or D31 depending on the bus size.  
>But how does this work in Big Endian?  Will an 8-bit bus run on D24..D31
>and a 16-bit bus on D16..D31?  Or does the chip solve this internally?
>  
>
In this case an instruction that writes a word or double word to the bus 
will write bytes in little endian order and so you have to manage the 
situation in software. More precisely you have to swap MSB and LSB on a 
word and revert all bytes in a double word and then write them to the bus.

>Best regards,
>Pieter Verstraelen
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>Yahoo! Groups Links
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