; subroutine DIV32 ; 32-Bit / 16-Bit to 32-Bit Quotient & remainder signed Divide ; 2's Complement Format ; ; input: r3, r2, r1, r0 = Dividend X ; r5, r4 = Divisor Y ; ; output: r3, r2, r1, r0 = quotient Q of division Q = X / Y ; r7, r6, r5, r4 = remainder ; Carry C is set if Y = 0, i.e. divide by 0 attempted ; ; calls: UDIV32, Cr0r3, Cr4r5, Mr0r3 ; ; alters: acc, flags, Bits 21H & 22H
DIV32: anl PSW, #0E7H ;Register Bank 0 mov a, r4 ;get divisor high byte orl a, r5 ;OR with low byte jnz div32_OK ;divisor OK if not 0 setb C ;else, overflow ret div32_OK: acall Cr0r3 ;2's comp -> Mag/Sign acall Cr4r5 ;2's comp -> Mag/Sign acall UDIV32 acall Mr0r3 ;Mag/Sign -> 2's Comp clr C ;divisor is not 0 ret ;done
Source: Maths Subroutines for the 8051 microcontroller, W.G.Marshall 2002
Related topics:
8051 Program - signed 8bit division | 8051 Program - unsigned 8bit division | 8051 Program - signed 16bit division | 8051 Program - unsigned 16bit division | 8051 Program - unsigned 32bit division | 8051 Program - memory subroutines | 8051 Program - math subroutines | 8051 Program - conversion subroutines
List of topics: 8051
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