user manual

A-55

INSTRUCTION SET REFERENCE

Hex Code in: Binary Mode = [A5][Encoding]

Source Mode = [Encoding]

Operation: DEC

(WRj) ← (WRj) – #short

DEC DRk,#short

Binary Mode Source Mode

Bytes: 32

States: 54

Hex Code in: Binary Mode = [A5][Encoding]

Source Mode = [Encoding]

Operation: DEC

(DRk) ← (DRk) – #short

DIV <dest>,<src>

Function: Divide

Description: Divides the unsigned integer in the register by the unsigned integer operand in register

addressing mode and clears the CY and OV flags.

For byte operands (<dest>,<src> = Rmd,Rms) the result is 16 bits. The 8-bit quotient is

stored in the higher byte of the word where Rmd resides; the 8-bit remainder is stored in the

lower byte of the word where Rmd resides. For example: Register 1 contains 251 (0FBH or

11111011B) and register 5 contains 18 (12H or 00010010B). After executing the instruction

DIV R1,R5

since 251 = (13 X 18) + 17; and the CY and OV bits are clear (see Flags).

Flags: The CY flag is cleared. The N flag is set if the MSB of the quotient is set. The Z flag is set if

the quotient is zero.

Exception: if <src> contains 00H, the values returned in both operands are undefined; the

CY flag is cleared, OV flag is set, and the rest of the flags are undefined.

[Encoding] 0 0 0 1 1 0 1 1 t t t t 0 1 v v

[Encoding] 0 0 0 1 1 0 1 1 u u u u 1 1 v v

CY AC OV N Z

0—✓✓✓

CY AC OV N Z

0—1??