see below, please. regards,
Richard Erlacher ----- Original Message ----- From: "Richard Gray" <[EMAIL PROTECTED]> To: <sdcc-user@lists.sourceforge.net> Sent: Sunday, September 07, 2008 11:46 PM Subject: Re: [Sdcc-user] documentation & open source generally > On Monday 08 September 2008 06:32:51 Richard Erlacher wrote: > <snip> >> You shouldn't let things such as that scare you. If you maintain order >> and >> discipline within your code, you can do it. ... easily ... and most >> assemblers have no quirks that would "mess you up" as HLL's often do. >> Believe me, the possibility that a HLL reduces the line count is not >> necessarily a blessing. What matters is the way in which the code is >> organized. Most MCU code is small, and even if quite large, it's often >> mostly table space. I often generate tables in a HLL on the PC (in >> BASIC, >> ... sometimes ... <cringe> ...) and then paste the output into an ASM >> source file. I come from that generation that was happy to have 256-byte >> EPROMS (they were reuseable!) so I try to be thrifty with code space. >> Compilers don't always help much with that. >> >> 4 k-lines? That's a small program. I would find something longer than >> 100 >> k-lines difficult to manage, would consider a HLL at 250 k-lines, and >> certainly would use a HLL if it got to be twice that long. Fortunately, >> MCU's generally don't require that much code. > <snip> > > OK, I was exaggerating to make a point. > > I wouldn't make assembler my starting point unless there was a really good > reason to do so. My latest efforts have mandated an assembler fragment > because I couldn't initialise the stack pointer and MMU any other way (not > sensibly anyway), but such is an example of where I use that medium - only > when there's no sensible alternative. > With most microcontrollers, there's good reason to do so, as they require MCU-specific initialization. It's possible, I suppose to write configuration parameters to the appropriate locations using HLL, but I'm not sure I'd do that. Some MCU's recognize certain SFR writes only if they occur within a specific time interval, and I'd guess there are many other reasons why one would want to ensure the precise timing of certain operations, for which ASM is essential. As a result, I'm guessing the ASM can't be eliminated entirely. Now, with a Z80, which is a microprocessor, rather than a single-chip microcontroller, with no on-chip I/O or memory, requiring initialization of on-chip resources, one might do without ASM, right up to the point at which external hardware requires precise timing. If it doesn't, well, you can do everything in 'C'. > > -- > Richard. > PGP Key-id: 0x5AB3D350 > > God doesn't play dice. > -- Albert Einstein > > ------------------------------------------------------------------------- ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Sdcc-user mailing list Sdcc-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sdcc-user
