🚀 go-pugleaf

On Fri, 30 Oct 2009 06:52:49 -0700 (PDT), MooseFET
<kensmith@rahul.net> wrote:

>On Oct 30, 4:57�am, Al Borowski <al.borow...@gmail.com> wrote:
>> > Briefly, the Modified-Harvard architecture used in the PIC devices
>> > separates the program memory from the data memory, in other words
>> > separates the ROM/FLASH program memory from the RAM.
>>
>> [...]
>>
>> Yes, but there's more to to a uC core then choosing between Harvard or
>> Von Neumann. I think most of the PICs quirks come from the other
>> decisions made.
>>
>> The PIC (up to 16 bit cores anyway) is an accumulator architecture -
>> you have to funnel everything through the W register.
>
>Going with accumulator model allowed Microchip to make the processor
>with fewer transistors. It is a trade off that can break either way.
>If you have a limit on the chip size you can make a higher performance
>processor that is harder to program.
>
>
>[....]
>> in the 16 bit core thankfully). Personally, I think the most annoying
>> thing about programming PICs in assembly are the btfsc (test a bit in
>> 'file', skip the next instruction if it's clear) and btfss (same thing
>> but skip if set) instructions. Why they couldn't just call these ifbit
>> and ifnbit, I don't know :-)
>
>Does ifbit mean skip if the bit is set or do the instruction if the
>bit is set?
>
>>
>> Back to the OP, great job Microchip on the video. It's a nice contrast
>> to TI, who recently sent misleading DMCA notices to people who tried
>> installing after-market OSs on their graphics calculators (http://news.cnet.com/8301-30685_3-10374284-264.html)
>>
>> Cheers,
>>
>> A;
>
>I still prefer the 8051.  It is way better.
>[ducks]

So do I. The 8051 family was/is great. 

But I found the varients of 8051 I used were obsolete on more than one
occassion causing problems. I'm still sourcing SAB80C517 at silly
prices for example.

I first used the PIC for very low cost apps around 1990 and found that
there was always an upgrade path which didn't obsolete my designs.

Secondly Microchip always have product available.  I recall one rep
trying to convert me to the ST6. Then he said ST are behind on
production and delivery was 4-6 months.

There are better micros than the PIC from an engineering perspective
but they are hard to beat from a production view point.