[EFI] Re: MegaSquirt

[Daniel Houlton]

Wayne Macdonald wrote:
> 
> I was just wondering why you chose the 68HC908GP32 instead of the
> 68HC912B32, The HC12 offers a number of improvements, It has 32 bit math,
> 768 bytes of EEProm , 10 bit A/D, 8 input/output timed capture/compare lines
> .......
> .......


Someone on the EFI332 list asked this a few weeks ago too.  
Here's Bruce's response:

-----------------------------------------------------------------

Date: Fri, 14 Sep 2001 16:31:49 -0400
From: Bruce Bowling <bbowling at earthlink.net>
To: efi332 at diy-efi.org
Subject: [EFI332] Re: MegaSquirt

Hello Kevin,

As you know, many processors would work here, and the HC12 is a really nice
family with better feature sets than the HC08.

The main reason was price, availabilty (you can get these from Digi-Key), the
HC908GP32 is the flagship HC08 part for Motorola and will be around for a long
time, it is automotive temp grade, there are really simple flash programming
interfaces (see applications note EB366 on the Mot www site - one can burn the
flash with only a MAX232 chip and free P&E software). Also, at 8 MHz internal
bus speed it is plenty fast, musch faster than the 1 MHz HC11 parts which are
used over and over in aftermarket ECUs. And part of the goal was to prove that 8
bits of ADC is all that is needed for the sensors.

Also, I like a challenge.....



Kevin Margitta wrote:

> Bruce, just out of curiosity..... Can I ask why you decided to go with
> the 08 over the 12 series from Motorola?  I've been working with both
> for a while now (mainly trip computer and diagnostic equipment with VFD
> stuff)and have basically dropped the 08 and concentrated on the 12.  I
> realize that the 08 is definitely more cost effective, but the 12 has
> better A/D resolution, other versions with much more memory available
> for upgrading, etc etc.
>
> Looking forward to your response,
>
> Kevin Margitta

--
- Bruce


-----------------------------------------------------------------

--Dan
houlster at inficad.com
http://www.inficad.com/~houlster/amigo.htm
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org