Post by thread:Parallax to MPlab

I am doing some similar conversions for a C Compiler I am converting that used to produce a source file for an 8051 style assembler for PIC's. The bad news is that there are no direct conversions for the conditional jump instructions you are looking at. The good news is all can be simulated on a PIC, but will require at least two, and sometimes quite a few PIC instructions. This isn't as bad as it seems since the 8051 is not a RISC device, so the number of clock cycles used for a jump is comparable to the 8051 equivalent, it is just a lot cleaner to look at the 8051 versions than the PIC versions. If you want to keep the clean look in you ASM files, I suggest you write macros that convert the old compare instructions into a sequence of PIC ones that do the same thing. Oh, one other caveat, many of the PIC equivalents will mess up one or other of the arguments (W or a register file). The csxx instruction are basically "compare and skip if true" instructions. They can be simulated simply for stuff like "csnz file": movf file,1 btfsc STATUS, ZERO skipee ; this is the instruction that will be skipped. Of course STATUS and ZERO are defines for your target device. A cjxx instruction like "cjz file, target" can be written as: movf file,1 btfsc STATUS, ZERO goto target ; this instruction will be skipped if file is NOT zero. These were simple, but it gets messier when you need to use the carry flag and the zero flag for comparisons like greater than or below. In these cases your code will have a few btfsx instructions and maybe a few local labels (or relative goto's) too. This is not intended to explain the whole process (I don't have time for that), but hopefully it will put you on the right path. HTH - Martin R. Green spam_OUTelimarTakeThisOuTbigfoot.com BTW - another gotcha is that other uC's allow direct file to file comparisons, while with PIC's you must move one register file into W and perform the comparison from there. It makes thing messier but it can be done. ---------- From: David Bramham[SMTP:.....d.bramhamKILLspam@spam@QUT.EDU.AU] Sent: Wednesday, August 13, 1997 6:33 PM To: PICLISTKILLspammitvma.mit.edu Subject: Parallax to MPlab Hi all, I have a copy of RCV2LCD.SRC for Parallax PIC Application.I would like to convert it to an MPlab ASM file .However,I have problems converting such statements as 'csne'and 'cjb'. Does anybody have either a this program in ASM file format or a list of conversions between the 2 codes. Many thanks David

David Bramham <.....d.bramhamKILLspam.....QUT.EDU.AU> wrote: > Hi all, > I have a copy of RCV2LCD.SRC for Parallax PIC > Application.I would like to > convert it to an MPlab ASM file .However,I have problems > converting such statements as 'csne'and 'cjb'. Does > anybody have either a this program in ASM file format or > a list of conversions between the 2 codes. David I also wanted to convert for Parallax to Microchip recently and was franticly searching for a suitable converter program. The all of a sudden it struck me..... You can do the entire translation with MLPAB! It works beautifully. This is what you do... You import the Parallax OBJ file in to memory (under File menu). The Parallax OBJ file is also INHX8M (Intel Hex 8-bit Merged format) format, so MPLAB has no problem importing it. Then you display the program memory window (under Window menu). This will give you the assembler together with line numbers and addresses. Select and copy this to a text file and you have your assembler. You'll have to manually edit it a bit to change the calls and goto's to labels again, but at least you will have a 100% correctly translated file. :) Hope this helps. Rgds Werner -- Werner Terreblanche users.iafrica.com/w/we/wernerte/index.htm EraseMEwterrebspam_OUTTakeThisOuTplessey.co.za (work) OR wernertespam_OUTiafrica.com (home) Plessey SA, PO Box 30451,Tokai 7966, Cape Town, South Africa or at home : Suite 251, PostNet X5061, Stellenbosch, 7599 Tel +27 21 7102251 Fax +27 21 7102886 Home +27 21 8872196 ------------------------------------------------------------