TAQOZ Reloaded v2.8 - Writing Inline Assembly Language
Here's my notes on writing TAQOZ words using in-line assembly language at version 15. I'll up-issue as I learn more.
Here's my notes on writing TAQOZ words using in-line assembly language at version 15. I'll up-issue as I learn more.
Comments
Just super Bob. I had a quick look and will have a better read of that later.
I took the time to read the document end to end and I can only repeat what Peter has already said. You must've prepared many, many quality docs in your career, obviously.
Thanks both, I expect there's a lot that can be added, there's plenty more features in TIA. I fixed some mistakes so worth downloading before rereading.
Very satisfying when a word assembles with no stack mismatch and then after a few more tweeks actually works. The reset button gets a lot of use as does the dump
and stack display commands! I like the conventional syntax in TIA, so many forth assemblers use RPN which makes adopting code from other assemblers a real chore. Plus I found writing assembler in tiny chunks and testing the word out interactively in TAQOZ is fun, you get constantly rewarded with another working word you can trust. Deserves wider recognition as a tool for seriously high speed applications with fewer bugs.
Deserves wider recognition as a tool for seriously high speed applications with fewer bugs.
You nailed it !
.
That's why Peter is trying to promote the TAQOZ in so many ways but, unfortunately, the majority of folks are stuck with the conventional tools and methods (for various reasons which we know all too well). The hardest part is to start with something new but once you see how productive one can be with TAQOZ it's even harder to stop using it, especially that it includes interactive assembler too. And many more
Hi Bob, this document is really very helpful! Great!
Perhaps you might add some lines about LOADMOD and COGMOD?
LOADMOD ( startadr number_of_longs -- ) will copy PASM code from hub into cog ram starting at fixed address.
COGMOD will execute any code, that has been loaded before.
code test ( value n -- value+3*n 0 ) add b,#3 sub a,#1 wz if_nz jmp #\@COGMOD '\ loop from start ret end AT test 2+ 4 LOADMOD \ loads the asm instructions of test into cog ram 10 5 COGMOD . . \ executes any loaded codeThe result is: 0 25
It took me some time to find #\@COGMOD as a way to implement the loop....
@Christof Eb.
That looks useful, I will add that to both the inline code and glossary documents, this was new information to me,
regards, Bob
Hi can someone help, please? -solved
I have now struggled for half a day to assemble some code with Taqoz 2.8 inline assembler and forward label reference for half a day, and cannot get it running.
The version with the { } comment works. It fills a buffer with Sync3 adc data. The code within the comment shall bring a positive edge trigger.
But if I delete the { }, jmp #la2 should skip the code until la2. Instead it does not work any more.
So how can I do a forward jump?
(setse4+waitse4 did not work too.)
Many thanks!
code fs3a ( d: stat c:aBuf b:len a:level -- d c b a ) '\ setse4 a '\ from tos mov r1,#0 '\ clear diff1 mov r2,#0 '\ clear diff2 .l0 testp #adcpin wc '\ waitse4 '\ wait for sample period done if_nc jmp #l0 rdpin r0,#adcpin '\ get SINC3 accumulator sub r0,r1 '\ compute sample add r1,r0 '\ update diff1 value sub r0,r2 '\ compute sample add r2,r0 '\ update diff2 value shr r0,#9 '\ #7 justify 14-bit sample zerox r0,#17 '\ #13 trim 14-bit sample, now use sample somehow { jmp #la2 cmp d,#2 wz '\ stat 0: wait f minus, 1: w plus, 2: sample if_z jmp #la2 '\ la2 cmp d,#1 wz '\ stat 0: wait f minus, 1: w plus, 2: sample if_z jmp #la3 '\ la3 cmp r0,a wc '\ status is 0 - wait for minus if_c mov d,#1 '\ new status 1 jmp #l0 la3 cmp r0,a wc '\ status is 1 - wait for plus if_nc mov d,#2 '\ new status 2 jmp #l0 } la2 wrlong r0,c '\ sampling write to buffer add c,#4 '\ next address in buffer djnz b,#l0 '\ loop for next period ret end : fillSync3Adc ( -- 0 1 2 3 ) \ with trigger 18 bit 512 clocks setSync3 2 \ trigger status 0 on stack: d aBuf \ Buffer address on stack: c aBufLen \ on stack: b adcReso 2/ \ trigger level on stack: a fs3a ;**Solved: I finally found the remark in PASM.fth, that forward references do only work for djnz!
**
@bob_g4bby
1. I think it should be helpful, if you could add some lines into your description about labels. While jumps backward do make no problems, forward jumps are only supported for djnz. jmp is not supprted. It took me several hours to find this "feature" because sometimes the forward jump seemed to work.
At the moment the best workaround seems to be to use the skip instruction. It needs one bit set for every instruction, that needs to be skipped.
I saw your article and thought the same thing - I will add the information on jumps.
Hi Bob,
although I tried, I could not get
....
ASM:
....
FORTH:
....
work. This switch back to Forth seems not to work?
Perhaps you could check this and put it into your paper?
Hi Bob,
in your passage "Taqoz temporary registers", it would be good to clarify, that some of these register names refer to the same cell.
xx, yy=r0, zz=r1, r2, r3, r4, acc=ac
I had some strange things going on, when I used both r1 and zz, thinking they would be independent...
Edit: For some reason this does not work always. For a better variant see #16.
Hi @bob_g4bby ,
I finally found out how the switch back from assembler to Forth is intended to work and think, that I was able to patch it:
--- switch from inline assembly back to Forth threads and continue compiling $31 := doNEXT \ was faulty FORTH ASSEMBLER pub POP, ( #d -- ) %000101011 %110101100_0 DSCZ ; pub FORTH: r0 POP, \ delete return address PTRA doNEXT #s CALLDS, end [C] ] ; FORTH : testB ( -- ) \ does work 1 \ to stack ." Before 1st Asm " dup . ASM: mov a,#2 FORTH: ." After 1st Asm " dup . ASM: mov a,#3 FORTH: ." After 2nd Asm " . ;Perhaps you would like to test it and include the patch into your tutorial?
Christof
Hi @"Christof Eb." ,
I can't get testB to run - which is strange. I see the first print statement only Before 1st Asm 1 and then Taqoz reboots.
I'm running KERNEL TAQOZ Forth for Parallax P2 Multicore MCU V2.10.0 'CHIP' 210812-1000 Prop_Ver G 320MHz. I downloaded _BOOT_P2.BIX from Peter Jakacki's website this morning.
It's probably a version thing.
Sorry Bob.
Hm, this drives me crazy. The inline code above did work yesterday in my setup and in the morning today but not then any more. - Now it works again. Tried terminal serial transmit delay - this seems not to be the problem.
One constellation crashs repeatable but only after 8 recompilations.
Edit: At the moment I think it might be an alignment problem jumping from hub to cog.???
@bob_g4bby
Hi,
the problem seems to be related somehow to code alignment. (?) At least I was able to influence the crashes inserting or not inserting a word before the ASM: I do not understand it. In addition I now learned that it is not a problem to overfill the hardware stack, which is implemented by a shifter.
Do you want to try the following?
FORTH ASSEMBLER pri PCNEXT _pc @ 12 + ; pub FORTH: end [C] ] ; FORTH : testD \ works 1 \ to stack \ crlf begin ASM: add a,#1 mov PTRA,##PCNEXT jmp #\$31 ' doNEXT FORTH: crlf dup . ASM: add a,#1 mov PTRA,##PCNEXT jmp #\$31 ' doNEXT FORTH: crlf dup . 1000 ms dup 10 > until drop ; testDUp to now I was not able to put the sequence
mov PTRA,##PCNEXT jmp #\$31 ' doNEXTinto the FORTH: macro. So this has to be added to the end of each assembler block.
@"Christof Eb." that code runs and doesn't crash Taqoz, but I don't see any of the numbers printed from the "crlf dup ." words. The number 1 is left on the data stack.
Oh, .... !
As this relays on "doNEXT" being located at $31 it would be interesting to make sure, that there is not a version conflict here.
TAQOZ# $31 cog@ .long --- FAE4_1F61 okIt would be interesting to hear, if you get that same result?
But I don't want to steal your time, with my buggy attempts....
Edit: My version comes from the Taqoz.zip in https://sourceforge.net/projects/tachyon-forth/files/TAQOZ/binaries/
The good thing of this version is, that you can have the sources and docu with it.
I've loaded your Taqoz version and now testD works fine for me - numbers 2 to 11 are printed
Peter tells me this code phrase will always produce the address of DONEXT :-
' CALL 8 + W@ 1- .L --- $0000_0031 okSee if that works for you, @"Christof Eb."
Your example could be modified with that to:-
FORTH ASSEMBLER pri PCNEXT _pc @ 12 + ; ' CALL 8 + W@ 1- := doNEXT pub FORTH: end [C] ] ; FORTH : testD \ works 1 \ to stack \ crlf begin ASM: add a,#1 mov PTRA,##PCNEXT jmp doNEXT ' doNEXT FORTH: crlf dup . ASM: add a,#1 mov PTRA,##PCNEXT jmp doNEXT ' doNEXT FORTH: crlf dup . 1000 ms dup 10 > until drop ; testDI've added your example code to 'Writing inline assembly language' - thank you very much for getting that going.
Hi Bob,
yes this works for the version from the zip too:
Parallax P2 TAQOZ RELOADED sIDE V2.8 'CHIP' Prop_Ver G 200MHz 210401-1230
I do not see the version from August as usable, because there is no documentation and or source for it. Up to this discussion I had thought, that these 2 versions of V2.8 would be pretty the same, but now we have learned, that Peter introduced some undocumented changements even into the very cog assembler kernel. I am really very thankful that Peter developed Taqoz, made it available and brought it to the maturity of V2.8. But on the other hand I do think, that the usability for me has improved very very much, since you wrote the documentation and since Peter stopped to change things....
Christof
Hi Bob,
today I found that at least in the version I use, there is a bug in LOADMOD: It does not drop it's 2 parameters.
So the work around is simply: Do a "2DROP" after using LOADMOD.
Probably worth to include this in the docu, as it takes a while to find such things....
Christof
A note has been added about a possible LOADMOD bug to the Taqoz Reloaded Glossary . I see it too since I'm now using the same version as you. Many thanks