At 07:23 AM 15/05/98 +0400, you wrote:
>Hello Sylvia Dokua Kwakye.
>
>> Hi all,
>>         I am fairly new to PICs and microcontrollers in general. I am
>> trying to make a decision between a PIC and the 6811 which I am a little
>> more familiar with. Apart from the smaller size and smaller instruction set
>> (ie, RISC features), what are other advantages does a PIC, say, the 16C73
>> have over  the 6811?
>>
>> Sylvia
>
>I suupose PIC16C73 has less power consumption than HC11. Also new PIC
>devices
>had build in brown-out protection circuit. PIC16C73 had less interrupt
>vectors
>(total reset and common int vector) I think there are another
>differencies too...
>
>I'll be pleasured to hear about differencies in prices between this
>chips too ;-)
>
>WBR Dmitry.
>
>


Sylvia

It depends on which side of the world we live in. The HC11 can be expensive,
and you should consider the reasons for not choosing this device:-

1/      The HC11 family was designed for GM namly for use in Autos for
engine control. Based on the original 6803 core with a few extra goddies

2/      As emission control is tightened, the processing power of the poor
little HCl1 has been pushed. Now ECU designers and manufactures are looking
at 68000 type controllers

3/      Motorola are now putting a large effort into the HC12 family, this
processor has the added advantage of a BDM port. It is also a good cross
between the HC16 and the HC05, some might say "The 8051 has had that for
ages" This is the process that I think you should look at

4/      The "Risk like core" of the PIC family is very simple

5/      Per MIP the PIC will draw less current

6/      Time critical loops and code size is easier to estimate in the PICs

7/      PICs are upward compatible (One can say the same for the HC11, but
these are realy only cross family compatible

8/      The HC11 will need careful attention to the entire design to ensure
that no external memory is required (The same can be said for the PIC,
however the PIC is economical on RAM and ROM)

9/      Good free development tools are offered for the PIC

10/     If you have problems using the PIC, then just ask the group (The
same could be said for the HC11)

11/     PICs have a large selection of peripheral devices like I2C SPI UARTS
TIMER/sand such.

12/     The PIC target market is micro controllers in this case, you have to
look at your target project and decide if it is a micro controller or a
micro processor that you require

13/     If developing from home, then (This is where I need help people).
The HC11 has the "Boot loader", if you use say the "F2" then you can
programme the on chip flash with a simple serial port (This will even work
if you have external flash etc). Now there may be the same thing offered by
other users with the PIC, but in general I think that a programmer is required.

14/     When did the last update to the HC11 family come out?  PIC are
progresive and always seem to be adding new members to the family


As a side note, you indicate that you have experience with the HC11. The
question is how much? PICs are a very different beast to use, and should not
be attempted until you feel confident about your programming, structuring
and debugging abilities (Not being nasty). I suggest that if you want to
look at a new chip, look at the HC12.