But the register layout . I wanted to like PICs, I really did. And I do see some places where they're the optimal choice. But, to try to squeeze everything through the one W register?!
-- Rich Webb Norfolk, VA
You have to remember, the PIC was designed to be cheap.
To be cheap, internal decoding had to be limited. So banking, instead of decoding a larger memory map.
Like the 8042 so many years ago.
Even with a "cheap" register set, a C compiler can be built to make programming easier for us grunts in the field.
I did not use PICs until the first C compiler came out. Does not really matter how bad the code is, your programming in C and not assembly.
Any C compiler take a lot of the tediousness out of programming.
my $0.02
don
On a sunny day (Sat, 16 Jan 2010 19:53:31 -0500) it happened Rich Webb wrote in :
Works OK here :-)
On a sunny day (Sat, 16 Jan 2010 22:43:57 -0700) it happened don wrote in :
C is OK for micros with a lot of memory. The small PICs like 12F... and 16F... I prefer to program in asm. The effort is the same, but in asm you know exactly what happens. When doing it in C you will have to look at the asm it generated many times... Once you did some in asm, then quickly you have collected a library of useful routines. Time critical requires asm anyways. Portability is not really an issue for those small things, often the hardware is unique, look at temp_pic for example:
The architecture of the 12/14 bit instruction set PICs is undeniably ugly.
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Beauty is in the eye...
But uglier even than an 8051 core.
I believe I've read something about the PIC dating back to the mid 1970's. Ah, heck, why say only that. Here it is:
The darned thing dates back to the mid-1970s! This is right in the middle of the transition from MSI to LSI in IC technology. 1kx1 dynamic ram chips were the rage of that day.
The 8051 dates back to about 1980. Some 5 years later. Which was well into the LSI side of IC design and where it was much more realizable. Memory sizes were much larger, too:
Plus, the PIC was designed at the time merely to offload I/O tasks not for general purpose computing, while the 8051 was designed at the outset as the sole microcontroller in a system. (The 8048 would be closer, in my mind, to serving PIC's designed services and may be more comparable.)
Those were all NMOS stuff at the time, too.
...
I like to think of it as a naked cpu. For some, an unclothed body is the most beautiful of all!
But now that I mention it, the PIC is 'ancient' and not so many ancient bodies are all that attractive, anymore. So...
Yeah. It can be said to be ugly.
For a given FAB process and yield, since the PIC was designed when every transmission gate and inverter meant something, it also means they can add a little more on the other end. Or so one would like to believe.
Jon
Well, it's upwards of 245 years old in uC years..
Despite facelifts etc., one feels one must avert one's eyes. But it does work. Speaking of the 12/16 core here primarily.
They do the job, and Sanghi has done yeoman duty in making them consistently available (and well-marketed). In the end, that's all that matters.
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
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