duane@mauve.samsung.com (Andrew Duane) (11/10/90)
We are moving to the 68040 chip soon, and are looking for two pieces of software relating to floating point operations. 1) The '40 doesn't support all of the floating point instructions the 68882 coporcessor did. We are looking for some software to emulate this subset of operations. 2) The exception frame for an unimplemented FP opcode is an F-line (type 2) frame. The saved PC is the instruction *AFTER* the bad one. Is backtracking to get the failed instruction hard. If so, we would want to get some code to do this. We called Motorola, and they charge $5K plus some licensing stuff that we don't need or want. Andrew L. Duane (JOT-7) w:(508)-685-7200 X122 Samsung Software America decvax!cg-atla!samsung!duane 1 Corporate Drive uunet/ Andover, MA. 01810 duane@samsung.com Only my cat shares my opinions, and she's Intel-based.
pdp8@athena.mit.edu (John W.F. McClain) (11/10/90)
Newsgroups: comp.sys.m68k Subject: Info wanted one buiding m68k systems Sender: pdp8@athena.mit.edu (John W.F. McClain) Reply-To: pdp8@athena.mit.edu (John W.F. McClain) Distribution: world Organization: Massachusetts Institute of Technology Keywords: books I have made 2 posting like this before, but I think they got lost. Sorry if you have seen this. I want to "play" with 680n0s a little, mabye even build a simple m68k box. Does any one know where I should start? Besides the m68k data manual are then any good books on designing/building with the m68k (as opposed to programing the m68k)? Thanks in advance John W.F. McClain pdp8@athena.mit.edu
bsw@cci632.UUCP (Brad Werner) (11/12/90)
In article <16871@samsung.samsung.com> duane@mauve.samsung.com (Andrew Duane) writes:
*[...] the 68040 chip [...]
* 1) The '40 doesn't support all of the floating point
* instructions the 68882 coprocessor did. We are looking
* for some software to emulate this subset of operations.
* 2) The exception frame for an unimplemented FP opcode is
* an F-line (type 2) frame. The saved PC is the instruction
* *AFTER* the bad one. Is backtracking to get the failed
* instruction hard. If so, we would want to get some code
* to do this.
*Only my cat shares my opinions, and she's Intel-based.
In section 9.3.6 of the 040 user's manual, (pg 9-12 in 1989 ed.)
it is noted that the FSAVE frame contains all the required info.
you need to emulate [to completion] the instruction, and it is
noted there that whereas the PC is as you mentioned, pointing
to the next instruction, the actual PC is in the FSAVE frame
as well as the command word (CMDREG1B). See sec. 9.7 "Floating-Point
State Frames" for the breakdown of the FSAVE frames. The exception
frame and the FSAVE frame together contain enough information for
an exception handler to attempt completion of the instructions.
Be careful of unimplemented data types. The manual notes that
the operand fetch has been done, and the destination for these
instructions may only be a register. There is enough information
there to make it pretty straight-forward. Good luck.
Disclaimer: I speak for myself && none other && vice versa;
Brad Werner; bsw@cci.com; ...!rochester!cci632!ccird1!bsw