$4D table mangling

[steveo]

just a thread so i can get some help in trying to play with table lookups in $4d, or at least so you can all watch me fail miserably

first time trying to mess with table lookups, so chances of me doing the obvious and failing miserably are high.

my goal is, want both tables to be re-ranged from 20kpa to 100kpa. i do a LOT of decel and very light crusing, and spend a ton of time 20-40kpa, so i want more fine grained control in that range, and there is NO way to force an LO3 above 100kpa.

i'd like to increase VE resolution too, but maybe that's next, since there's very little free space to shove stuff around with only a 4k bin.

relavent code;

;~~~~~~~~~~~~~~~~
;-Main %VE table
;~~~~~~~~~~~~~~~~
;
LD278   FCB       0		;row offset
        FCB      16		;Col offset
        FCB       8		;# of cols

;    RPM/1k  .4   .8  1.2  1.6  2.0  2.4  2.8  3.2 ;kPa
;              
        FCB  50,  49,  54,  57,  60,  62,  63,  65 ; 30
        FCB  51,  52,  55,  63,  69,  76,  86,  90 ; 40
        FCB  53,  54,  61,  65,  79,  88,  99, 103 ; 50
        FCB  55,  59,  75,  82,  86,  94, 101, 108 ; 60
        FCB  65,  71,  88,  91,  93,  99, 110, 116 ; 70
        FCB  95, 107, 112, 108, 103, 103, 111, 120 ; 80
        FCB  98, 106, 121, 121, 119, 119, 122, 127 ; 90
        FCB  99, 107, 121, 125, 124, 125, 125, 129 ;100
        FCB  99, 106, 120, 127, 126, 124, 126, 130 ;110

;~~~~~~~~~~~~~~~~
;main %VE lookup
;~~~~~~~~~~~~~~~~
;
LD596   LDAB    L001B		;RPM/25
        BPL     LD59C		;bra if <3200
;
        LDAB    #$0080		;3200 rpm
;
LD59C   LDX     #LD278		;%VE table
        JSR     LFB99		;Do 3D lookup
        ADDA    L00AC		;add %VE in
        BCC     LD5A8		;Bra if overflow
;
        LDAA    #$00FF		;clr overflow
;
LD5A8   STAA    L00AC		;Store it, %VE

;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;>
;>3D lookup routine
;>
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;
LFB99   SUBA    $0000,X		;Subtract row offset from A
        BCC     LFB9E		;Bra if > offset
;
        CLRA 			;Clr A 
;  
LFB9E   SUBB    $0001,X		;Subtract column offset from B
;
        BCC     LFBA3		;Bra if > offset
;
        CLRB			;Clr B
;    
LFBA3   STAB    L004B		;tmp storage
        LDAB    #$0010		;
        MUL  			;Calc column offset   
        PSHB			;Push the leftovers to the stack
;    
        LDAB    $0002,X		;Load in # of cols. into B
        PSHB  			;Push that to the stack too  
        MUL 			;Offset in A x # cols.      
        ABX 			;Add in offset to X
;   
        INX			;Addr +1     
        INX 			; "    
        INX 			; "   
        PSHX 			;Addr of column ----> stack   
        LDAA    L004B		;Load row offset into A
        BSR     LFB7B		;Go do 2D lookup
;
        STAA    L004A		;tmp storage
        LDAA    L004B		;load row offset into B
        PULX    		;Get column address off the stack
        PULB  			;Get # of columns from stack  
        ABX 			;Add # of columns to X, go over one row    
        BSR     LFB7B		;2D lookup, get value next to it
        TAB			;Value ----> B     
        LDAA    L004A		;Get that value back into A
        BRA     LFB83		;Go interpolate it and return

[jim_in_dorris]

Steveo, I have never played with $4d, but I do understand assembly language programming really well, so maybe I can help out. Changing the table itself isn't too difficult, but what values are you going to want for the 20 kpa row? And as far as increasing resolution, do you mean making the table bigger? In a 4k bin that might be a problem. You also will have to make sure to check boundary values at the high and low end of the table to ensure you don't exceed them in the call.

[steveo]

oh this too, most important part ..

;-Check if use Baro/Raw map is flagged, else use SD MAP for %VE lookup
;
        LDAA    L0024		;Load SD map
        LSRA 			;/2   
        LDAB    LD006		;opt word
        BITB    #$0008		;Test b3, do baro fuel corr.
        BEQ     LD596		;Bra if ==0
;
;-Do raw map conv. and use for %VE lookup, takes baro press. into account.
;
        LDAA    L0027		;Raw map
        CMPA    L00FE		;Baro pressure
        BCS     LD58C		;Bra if < baro pressure
;
        LDAA    #$007F		;127		
        BRA     LD596		;Bra
;
LD58C   LSRA  			;Raw Map /2  		
        ADDA    #$000E		;15, offset
        LDAB    L002F		;factor from Baro lookup
        MUL  			;(MAP val. x factor)   
        ASLD			;x2    
        ASLD 			;x2   
        SUBA    #$0020		;-32

[steveo]

Steveo, I have never played with $4d, but I do understand assembly language programming really well, so maybe I can help out. Changing the table itself isn't too difficult, but what values are you going to want for the 20 kpa row?

basically i just want to shift the entire table -10kpa in range, so instead of being 30kpa-110kpa i get 20kpa-100kpa.

(obviously this is a lookup thing instead of modifying the table itself...)

[steveo]

there's full disassembly in the $4d sticky if you're interested in helping

[jim_in_dorris]

I will take a look at it. Again, the only thing you probably need to change is a couple of bytes in the lookups and putting the values you want in the 20kpa row. Do you see 20kpa that often?

[steveo]

never really looked at it too hard, but it's interesting that there are two SD lookup modes, one with barometric pressure compensation and one without.... and that bit isn't set in ANY factory calibrations...

[steveo]

Do you see 20kpa that often?

well, yeah. cruising range is ~30kpa and decel is 20kpa. i'd really like to be able to manipulate spark and fuel @20-30kpa a bit more effectively. especially since i never hit 110kpa, so that entire row is useless.... it'd be nice to lose it in favor of better low end tuning.

[jim_in_dorris]

Does Decel use the VE table or a DFCO table? You need to pay attention to what happens in decel before you go changing the table.

[steveo]

yes. i do have to pay attention to that. let me have a look at it.

[steveo]

on an initial glance, it doesn't seem to 'use' the ve table at all; it seems to be straight up coolant temp lookup that's multiplied into BPW. and it's controlled by a status bit set by a threshold.

;BPW = BPWC x AFR x VE x MAP x Cool corr. x BLM corr. x DFCO x decel. x FPV corr.
; +/- INT prop. term

i think the author of this program intended anything below 30kpa to start nearing decel mode, and just run a multiplier to start enleanment

i dont want to have a ve table that runs over decel or anything, but i do think there's quite a bit of territory JUST UNDER 30kpa that i play around in that i could fine tune for driveability.

[jim_in_dorris]

Well, I will take a look at it and make a guess, but right now I think that it might be doable without too much effort.

[steveo]

its lookin' that way, if you'd have a look i'd appreciate it, but im going to stare at it too see if i can figure it out.

[jim_in_dorris]

Steveo, I looked at the code a little tonight, and the only thing I am not sure about is the use of the raw map signal. Other than that, It should be just as simple as changing the table. If the code does what I think, the map/ raw baro merely gives one of the offsets into the table. RPM is the other. I am not 100% sure what the boundary values are for RAW/ baro, and MAP, but so long as the value doesn't resolve outside the table boundaries you should be ok. What you might want to do is to look at the MAP conversion routine and see what values are possible coming out of the a/d converter reading the MAP.

[steveo]

yeah it does look that easy; doesn't it. i'll try a few approaches tonight and see if it runs. im lucky; i have a nice chunk of unused code there (the barometric compensation branch) that i can use for my own purposes.