Re: Clarification about Atmega128



In article <1121928186.089133.63730@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Tamilmaran S <tamilmaranz@xxxxxxxxx> writes
Hi all,
     We are using atmega128 for one of our project. I heard that it is
a 8 bit microcontroller, ok its accumulator and its data bus are 8 bit
width. Then what about is address bus, is it also 8 bit width? Because
for this 8 bit it can address only up to 2^8 = 256 location. Then how
it can address 4096 SRAM (4K) and 131072 Flash (128K). Can anybody
clear me on this doubt? Thank you

"8 bit" refers to the data bus width, in every micro I have ever heard of.

In the mega128 the address bus is 16 bit and each flash location is a word (16 bits) rather than a byte. Hence there are 64K of flash locations but actually 128K bytes of flash.
--
Tim Mitchell
.




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