baum@apple.UUCP (Allen J. Baum) (03/03/88)
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I am puzzled by some things in the RPM-40 instruction set encoding. The ISSCC
arcticle showed the opcode formats, including the load/store format, which
looks like: 2 1 1 4 4 4
op ld/st s dst base offset
Now, I thought I was told that the 's' bit was for doing signed ld/st, but
a signed store makes no sense. I also thought that I was told that the
load/store ops were word/halfword/byte, but the encoding doesn't mention them,
and load word signed makes no sense, either. So, GE guys, whats the story?
Also the XPLD (which I assume is eXternal Processor LoaD) doesn't store.
Finally, could someone explain in just a little more detail what the memory
protection scheme is? Thanks a lot.
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