MPLABX 1.60, MCC18 v3.43, Windows/Linux
Project option: C18(Global Options)/MCC18/Default Storage Class: Static
Small memory model
 | | | | Код: !void main(void) {
!volatile near int a,b;
!volatile near long c;
! a = 38342;
0xA6: MOVLW 0xC6
0xA8: MOVWF a, ACCESS
0xAA: MOVLW 0x95
0xAC: MOVWF 0x1, ACCESS
! b = -30342;
0xAE: MOVLW 0x7A
0xB0: MOVWF b, ACCESS
0xB2: MOVLW 0x89
0xB4: MOVWF 0x3, ACCESS
! c = a * b;
0xB6: MOVF b, W, ACCESS
0xB8: MULWF a, ACCESS
0xBA: MOVFF PRODL, c
0xBC: NOP
0xBE: MOVFF PRODH, 0x5
0xC0: NOP
0xC2: MULWF 0x1, ACCESS
0xC4: MOVF PRODL, W, ACCESS
0xC6: ADDWF 0x5, F, ACCESS
0xC8: MOVF 0x3, W, ACCESS
0xCA: MULWF a, ACCESS
0xCC: MOVF PRODL, W, ACCESS
0xCE: ADDWF 0x5, F, ACCESS
0xD0: CLRF 0x6, ACCESS
0xD2: CLRF 0x7, ACCESS
0xD4: BTFSS 0x5, 7, ACCESS
0xD6: BRA 0xDC
0xD8: SETF 0x6, ACCESS
0xDA: SETF 0x7, ACCESS
! while(1);
0xDC: BRA 0xDC
| | | | |
Project option: C18(Global Options)/MCC18/Default Storage Class: Static
Large memory model
| | | | Код: !void main(void) {
!volatile int a,b;
!volatile long c;
! a = 38342;
0xA6: MOVLB 0xE
0xA8: MOVLW 0xC6
0xAA: MOVWF 0xA, BANKED
0xAC: MOVLW 0x95
0xAE: MOVWF 0xB, BANKED
! b = -30342;
0xB0: MOVLW 0x7A
0xB2: MOVWF 0xC, BANKED
0xB4: MOVLW 0x89
0xB6: MOVWF 0xD, BANKED
! c = a * b;
0xB8: MOVF 0xC, W, BANKED
0xBA: MULWF 0xA, BANKED
0xBC: MOVFF PRODL, c
0xBE: NOP
0xC0: MOVFF PRODH, 0xE0F
0xC2: NOP
0xC4: MULWF 0xB, BANKED
0xC6: MOVF PRODL, W, ACCESS
0xC8: ADDWF 0xF, F, BANKED
0xCA: MOVF 0xD, W, BANKED
0xCC: MULWF 0xA, BANKED
0xCE: MOVF PRODL, W, ACCESS
0xD0: ADDWF 0xF, F, BANKED
0xD2: CLRF 0x10, BANKED
0xD4: CLRF 0x11, BANKED
0xD6: BTFSS 0xF, 7, BANKED
0xD8: BRA 0xDE
0xDA: SETF 0x10, BANKED
0xDC: SETF 0x11, BANKED
! while(1);
0xDE: BRA 0xDE
| | | | |
Project option: C18(Global Options)/MCC18/Default Storage Class: Auto
Small memory model
| | | | Код: !void main(void) {
0xA6: MOVFF FSR2L, POSTINC1
0xA8: NOP
0xAA: MOVFF FSR1L, FSR2L
0xAC: NOP
!volatile int a,b;
!volatile long c;
! a = 38342;
0xAE: MOVFF FSR1L, FSR0L
0xB0: NOP
0xB2: MOVFF FSR2H, FSR0H
0xB4: NOP
0xB6: MOVLW 0xC6
0xB8: MOVWF POSTINC0, ACCESS
0xBA: MOVLW 0x95
0xBC: MOVWF POSTDEC0, ACCESS
! b = -30342;
0xBE: MOVF FSR2L, W, ACCESS
0xC0: ADDLW 0x2
0xC2: MOVWF FSR0L, ACCESS
0xC4: MOVFF FSR2H, FSR0H
0xC6: NOP
0xC8: MOVLW 0x7A
0xCA: MOVWF POSTINC0, ACCESS
0xCC: MOVLW 0x89
0xCE: MOVWF POSTDEC0, ACCESS
! c = a * b;
0xD0: MOVFF FSR2L, FSR0L
0xD2: NOP
0xD4: MOVFF FSR2H, FSR0H
0xD6: NOP
0xD8: MOVFF POSTINC0, c
0xDA: NOP
0xDC: MOVFF INDF0, 0x5
0xDE: NOP
0xE0: MOVF FSR2L, W, ACCESS
0xE2: ADDLW 0x2
0xE4: MOVWF FSR0L, ACCESS
0xE6: MOVFF FSR2H, FSR0H
0xE8: NOP
0xEA: MOVFF POSTINC0, 0x6
0xEC: NOP
0xEE: MOVFF INDF0, 0x7
0xF0: NOP
0xF2: MOVF 0x6, W, ACCESS
0xF4: MULWF c, ACCESS
0xF6: MOVFF PRODL, __tmp_0
0xF8: NOP
0xFA: MOVFF PRODH, 0x1
0xFC: NOP
0xFE: MULWF 0x5, ACCESS
0x100: MOVF PRODL, W, ACCESS
0x102: ADDWF 0x1, F, ACCESS
0x104: MOVF 0x7, W, ACCESS
0x106: MULWF c, ACCESS
0x108: MOVF PRODL, W, ACCESS
0x10A: ADDWF 0x1, F, ACCESS
0x10C: CLRF b, ACCESS
0x10E: CLRF 0x3, ACCESS
0x110: BTFSS 0x1, 7, ACCESS
0x112: BRA 0x118
0x114: SETF b, ACCESS
0x116: SETF 0x3, ACCESS
0x118: MOVF FSR2L, W, ACCESS
0x11A: ADDLW 0x4
0x11C: MOVWF FSR0L, ACCESS
0x11E: MOVFF FSR2H, FSR0H
0x120: NOP
0x122: MOVFF __tmp_0, POSTINC0
0x124: NOP
0x126: MOVFF 0x1, POSTINC0
0x128: NOP
0x12A: MOVFF b, POSTINC0
0x12C: NOP
0x12E: MOVFF 0x3, POSTINC0
0x130: NOP
! while(1);
0x132: BRA 0x132
| | | | |
Project option: C18(Global Options)/MCC18/Default Storage Class: Auto
Large memory model
| | | | Код: !void main(void) {
0xA6: MOVFF FSR2L, POSTINC1
0xA8: NOP
0xAA: MOVFF FSR1L, FSR2L
0xAC: NOP
0xAE: MOVLW 0x8
0xB0: ADDWF FSR1L, F, ACCESS
!volatile int a,b;
!volatile long c;
! a = 38342;
0xB2: MOVLW 0xC6
0xB4: MOVWF POSTINC2, ACCESS
0xB6: MOVLW 0x95
0xB8: MOVWF POSTDEC2, ACCESS
! b = -30342;
0xBA: MOVLW 0x7A
0xBC: MOVWF PRODL, ACCESS
0xBE: MOVLW 0x2
0xC0: MOVFF PRODL, PLUSW2
0xC2: NOP
0xC4: MOVLW 0x89
0xC6: MOVWF PRODL, ACCESS
0xC8: MOVLW 0x3
0xCA: MOVFF PRODL, PLUSW2
0xCC: NOP
! c = a * b;
0xCE: MOVLW 0x2
0xD0: MOVFF PLUSW2, 0x8
0xD2: NOP
0xD4: MOVLW 0x3
0xD6: MOVFF PLUSW2, 0x9
0xD8: NOP
0xDA: MOVFF POSTINC2, 0xD
0xDC: NOP
0xDE: MOVFF POSTDEC2, 0xE
0xE0: NOP
0xE2: CALL 0x114, 0
0xE4: NOP
0xE6: MOVFF 0x6, __tmp_0
0xE8: NOP
0xEA: MOVFF 0x7, 0x15
0xEC: NOP
0xEE: CLRF 0x16, ACCESS
0xF0: CLRF 0x17, ACCESS
0xF2: BTFSS 0x15, 7, ACCESS
0xF4: BRA 0xFA
0xF6: SETF 0x16, ACCESS
0xF8: SETF 0x17, ACCESS
0xFA: MOVLW 0x4
0xFC: MOVFF __tmp_0, PLUSW2
0xFE: NOP
0x100: MOVLW 0x5
0x102: MOVFF 0x15, PLUSW2
0x104: NOP
0x106: MOVLW 0x6
0x108: MOVFF 0x16, PLUSW2
0x10A: NOP
0x10C: MOVLW 0x7
0x10E: MOVFF 0x17, PLUSW2
0x110: NOP
! while(1);
0x112: BRA 0x112
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Все пак не очаквай, че като има хардуерен множител ще умножи две 16-битови числа с няколко инструкции, прочети какво вършат MULLW и MULWF и ще разбреш защо е така.
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Сега го правя по изкуствен начин, умножавайки байт по байт и събирайки. Трябва ми умножение 16 x 16 бита, резултата от което се записва в 32 битова променлива. Не ми е проблем и така, ама кода за едно мижаво умножение е 6-7 реда, и ако го чета след някоя и друга година, има да се дзверя доста.
