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 Robotics / RCX / 1850
1849  |  1851
Subject: 
Re: Motor Control Register (0xf000)
Newsgroups: 
lugnet.robotics.rcx, lugnet.robotics.rcx.legos
Date: 
Wed, 20 Nov 2002 22:20:22 GMT
Viewed: 
4178 times
  
Mark Riley <markril@hotmail.com> wrote:
It also turns out that there are 8 bytes of external RAM that peek
through at addresses 0xff80-0xff87.

Yeah, I missed that, I'll add that to the notes.

I bet the H8 designers left this little hole just so these instructions
could be used on external devices.

Too bad they didn't document the hole well enough to make it obvious to the
people at Lego, who apparently had no idea.  They use "mov.w rx,@0xf000:16"
all over the place instead of the shorter "mov.w rx,@0x80:8".  Anyways.
The hole is clear enough on the memory map, but the whole instruction-size
advantage of the hole is not clear at all I don't think.

-Kekoa



Message is in Reply To:
  Re: Motor Control Register (0xf000)
 
It also turns out that there are 8 bytes of external RAM that peek through at addresses 0xff80-0xff87. Writes to these locations also affect the motor control register. I suppose there's a small advantage in using these registers to control the (...) (22 years ago, 14-Nov-02, to lugnet.robotics.rcx, lugnet.robotics.rcx.legos)

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