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Re: [avr-gcc-list] Calling function with hard coded address

From: Claude Sylvain
Subject: Re: [avr-gcc-list] Calling function with hard coded address
Date: Thu, 02 Nov 2006 17:35:59 -0500

Hello J'org,

>> Claude Sylvain wrote:

>> GCC-AVR do not seem to support EICALL, so address space for function
>> pointers are limited to the first 64K.

> J"org wrote:

> This is wrong.  EICALLs are only needed for devices with *more* than
> 128 KiB of ROM, as the JUMP/CALL addressing uses 16-bit word
> addresses.  ATmega640/1280/1281 appear to support EICALL anyway,
> probably because the simply share the CPU code with their larger
> siblings ATmega2560/2561.  EIND is effectively ignored on these
> devices.

Euh... Yes, you are right (I am wrong).
I am new to the AVR MCU, and I was thinking that Z register is a
byte pointer, instead of a word pointer.  Now I understand  :-)

Sorry :=(


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