I used the HC11 for half a dozen project 5 to 10 years ago.
Right now, I am finishing two projects that use the HCS08 (9S08GT32) and two
that use a regular HC08 (908JB8).
The HCS08 parts in volume are starting to compete with some of the
8051's
and other more inexpensive micro's.
The HC08 core does not have many registers, just A and X or A and HX (a 16
bit index register). The HC11 has the A&B/D registers and another index
Y.
If you write in assembler and try to do some 16 bit math, you might notice
the difference. In C, you won't.
The HCS08 has flash, BDM, and a very versatile clock. You can run the clock
from an internal oscillator or an external crystal. The internal PLL
produces a little bit of dithe, but is not an issue for most applications.
The HCS08 bus clock will run up to 20MHz. If I remember correctly, the HC11
internal clock only ran at 4-5MHz, but that was years ago.
The varient that I am using has the usual basic peripherals, two timers, two
uarts, spi, 8/10bit ADC. It also has some very low current shutdown modes
that are useful for battery powered applications. It will also run at lower
voltages, down to 1.8VDC.
The RTI clock on the HCS08 is a little annoying. It is not accurate at all
(+/- 30%) without an external crystal and it will only run in stop modes,
which don't work with debugging. The all internal clock is very nice
when
board area is tight. But if you are depending on maintaining time for a
battery based application, you will probably need an external crystal.
Motorola was offering the Metrowerks compiler and debugger for free, with a
4K object code limit. I needed to upgrade to the 32K version for one of my
applications. My P&E Micro debugger pod cost about $300.
That's my 2 cents,
Sheldon
----- Original Message -----
From: "drleonardok" <>
To: <>
Sent: Wednesday, February 04, 2004 6:59 PM
Subject: [m68HC11] HC11 vs HCS08?
> What are the differences between HC11 & and
the new HCS08?
> Your response is appreciated.
>
> Regards
> Leo
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