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Rockbox mail archiveSubject: Re: Another port, is it possible?Re: Another port, is it possible?
From: Bluechip <csbluechip_at_gmail.com>
Date: Sat, 18 Aug 2007 11:05:33 +0100 At 10:47 18/08/2007, you wrote: >Vladimir Pantelic wrote: > > > The data sheet says 8bit! There is a DSP that does the MP3 decoding and > > a DMA controller, so most likely the z80 does little besides reading the > > FAT filesystem and setting up the DMA to pipe data from Flash to the DSP. > >Actually the Z80 is an 8-bit CPU with some 16-bit extensions. For >example it can combine six 8-bit registers into three 16-bit registers, >and do some simple arithmetic on them (add/sub). This may not sound >impressive, but it is way easier to program than a pure 8-bit CPU like >the 6502/6510 which doesn't know of 16-bit at all. There are registers other than BC DE and HL which behave as 16bit "register-pairs", not least of all the index registers IX and IY, there are also shadow registers and 16bit memory accessing instructions to consider above and beyond a 'pure' 8bit machine. BC Received on 2007-08-18 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |