Re: Advice on uC selection wanted - driving microsteppers etc

On Tue, 29 Apr 2008 08:41:07 GMT, "Peter Dickerson"
<firstname.lastname@xxxxxxxxxxxxxxxx> wrote:

OK, I'll follow up on myself. I am now looking at the STR911FAW42X6 (or even
STR912FAW44X6) from ST. It has 96K RAM and 256K+32K Flash (or 512K+32K).
Thats more than I budgeted for and at 96 MHz is about twice the speed I
need. It looks like it uses quite a lot of power but thats not a real
problem for me (about 50W used by lamps so a few hundred mW isn't a
problem). The timers look like they can be updated by DMA so I might even be
able to accelerate the motors with only DMA intevention.

In use, these parts are slower than a 60Mz LPC2xxx. Our benchmarks
indicate by about 15-20%, very much dependent on the code. They
race through straight-line code, but the branch logic is awful.

The 96k RAM is wonderful, especially with Ethernet. We get
excellent throughput on our PowerNet TCP/IP stack.

The peripherals are the usual weird ST mix, and many of them
have 16 bit registers/counters rather than 32 bit ones. If they
fit your requirements, it could be a good choice.

Stephen


--
Stephen Pelc, stephenXXX@xxxxxxxxxxxx
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
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