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> At the time that we had our _great_ talk/discussion/etc at the CCC, I was
> about 20hrs behind on my sleeping schedule, so I can't quite remember what
> microcontroller we were going to use. (Of course it doesn't help that I
> wouldn't recognize a microcontroller if it bit me in the ass :)
Our intention is to use the 'SH7041'-Cpu, made by hitachi.
Hitachi uses 3 diffenent scheems for theier parts-numbering,
so you might have trouble identifying the right part:
There are 3 basic 'evolution steps' for these risc-cpus:
SH1 - First generation, in production since 1995, production-end in 2000
SH702x - Cheap cpus, no internal a/d, less internal memory
SH703x - Standard derivates of the SH1-Cpu
SH2 - Second generation, advanced cpu-core (cache, new opcodes etc.)
Hitatchi tells all customers to upgrade their SH1-Design to SH2.
Even the SH2 is much more powerful than the SH1 was, the price
for the SH2 is about the same and will be less than SH1 soon !
Although the SH2 includes many enhancements, it is really a
re-design of the SH1, so these two cpus are not too different
in many aspects. Production for SH2 has started and it will
stay in production for a "long time" (hitachi-statement).
SH704x - Standard derivates of the SH2-Cpu
SH7040 - SH2, 112_Pins/64K_Rom
SH7041 - SH2, 144_Pins/64K_Rom <--- That's our device !
SH7042 - SH2, 112_Pins/128K_Rom
SH7043 - SH2, 144_Pins/128K_Rom
SH3 - Third generation, "very advanced" cpu-core
These cpus are still similar to the SH1/SH2, but they contain
a MMU and are optimized for even higher cpu-power. They are
intended to be used on handheld systems. Windows-ce can be
run on that cpu (not on SH1/SH2 - because windows needs the MMU).
The major disadvantage for these devices is, that they don't
contain a lot of on-board-i/o. Just the bare cpu - that's it...
However hitachi plans to produce more specific devices, too.
The part-number for any cpu is composed by a hitachi-special-scheeme:
For our cpu (SH7041) with internal otp-eprom this would be HD6477041xxx.
"HD" means hitachi/digital, "64" means a cpu, "7041" as shown above,
anything following indicates voltage (5/3V) and temperature-range.
The GNU-compiler supports code-generation for SH1 and SH2 (selectable).
They can't produce code for SH3-Cpus, as far as i know (will change soon...).
P.S. One of the major advantages of these cpus is, that they are flat if
they lie (upside down) around on your kitchen floor. This means
that they don't stick in your feets if you step on it !
Big advantage - don't think intel can do that !!!
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