Bit Angle Modulation (BAM) in a PIC

[Mike, K8LH]

Darrel,

I think these Gentlemen may be having a little fun at your expense as they try to get a rise out of you (LOL). That's the only reason I can think of for avoiding a simple question and for becoming a bit offensive when challenged.

My precalculated "output table" or "toggle table" MIBAM method should work fine with 13 or 14 bit duty cycle values but as you've already determined I can only get refresh rates of 610-Hz (8-chan, 13-bit, 200-nsec step) or 305-Hz (16-chan, 13-bit, 400-nsec step), etc., when using an 18F' device and 40-MHz clock (Tcy = 100-nsec). ISR "overhead" would be about 77% for the example below but could be improved with some structural changes.

Take care. Kind regards, Mike

;
;  8-chan (port b), 13-bit, 200-nsec (1638.4-usec period), 610-Hz
;
v_isr_h
        movff   bdat+12,LATB    ; b12 data        (2048T)
        inDlyCy(2048*tStep-2)   ; half 2^12
        movff   bdat+11,LATB    ; b11 data        (1024T)
        inDlyCy(1024*tStep-2)   ; half 2^11
        movff   bdat+10,LATB    ; b10 data        (512T)
        inDlyCy(512*tStep-2)    ; half 2^10
        movff   bdat+09,LATB    ; b9 data         (256T)
        inDlyCy(256*tStep-2)    ; half 2^9
        movff   bdat+08,LATB    ; b8 data         (128T)
        inDlyCy(128*tStep-2)    ; half 2^8
        movff   bdat+07,LATB    ; b7 data         (64T)
        inDlyCy(64*tStep-2)     ; half 2^7
        movff   bdat+06,LATB    ; b6 data         (32T)
        inDlyCy(32*tStep-2)     ; half 2^6
        movff   bdat+05,LATB    ; b5 data         (16T)
        inDlyCy(16*tStep-2)     ; half 2^5
        movff   bdat+04,LATB    ; b4 data         (8T)
        inDlyCy(8*tStep-2)      ; half 2^4
        movff   bdat+03,LATB    ; b3 data         (4T)
        inDlyCy(4*tStep-2)      ; half 2^3
        movff   bdat+02,LATB    ; b2 data         (2T)
        inDlyCy(2*tStep-2)      ; half 2^2
        movff   bdat+01,LATB    ; b1 data         (1T)
        inDlyCy(1*tStep-2)      ; half 2^1 (0 delay)
        movff   bdat+00,LATB    ; b0 data         (1T)
        inDlyCy(1*tStep-2)      ; full 2^0 (0 delay)
        movff   bdat+01,LATB    ; b1 data         (1T)
        inDlyCy(1*tStep-2)      ; half 2^1 (0 delay)
        movff   bdat+02,LATB    ; b2 data         (2T)
        inDlyCy(2*tStep-2)      ; half 2^2
        movff   bdat+03,LATB    ; b3 data         (4T)
        inDlyCy(4*tStep-2)      ; half 2^3
        movff   bdat+04,LATB    ; b4 data         (8T)
        inDlyCy(8*tStep-2)      ; half 2^4
        movff   bdat+05,LATB    ; b5 data         (16T)
        inDlyCy(16*tStep-2)     ; half 2^5
        movff   bdat+06,LATB    ; b6 data         (32T)
        inDlyCy(32*tStep-2)     ; half 2^6
        movff   bdat+07,LATB    ; b7 data         (64T)
        inDlyCy(64*tStep-2)     ; half 2^7
        movff   bdat+08,LATB    ; b8 data         (128T)
        inDlyCy(128*tStep-2)    ; half 2^8
        movff   bdat+09,LATB    ; b9 data         (256T)
        inDlyCy(256*tStep-2)    ; half 2^9
        movff   bdat+10,LATB    ; b10 data        (512T)
        inDlyCy(512*tStep-2)    ; half 2^10
        movff   bdat+11,LATB    ; b11 data        (1024T)
        inDlyCy(1024*tStep-802) ; half 2^11
        rcall   prep            ; rebuild bdat array
        movff   btmp,LATB       ; b12 data        (2048T)
        retfie  FAST            ;
;