Echelon Neuron - Manual (Page 95)

DIV (Divide)
The DIV instruction performs integer division. The DIV instruction uses the
implicit addressing mode. The instruction divides the unsigned integer dividend
value in NEXT by the unsigned integer divisor value in TOS. The quotient result
is placed in TOS. The remainder, if any, is placed in NEXT. Thus, this
instruction implements the following equation:
TOS
TOS
NEXT ⇒
, with remainder in NEXT
Division by zero has the following effects:
• The quotient in TOS is set to 0xFF.
• The remainder in NEXT is unchanged from the value of the dividend.
• A level 3 exception (subtrap 1), if enabled, is fired. This exception does
not cause a device reset.
Recommendation: Use the _div16 or _div16s system functions to divide
unsigned or signed 16-bit numbers, and use the _div8s system function to divide
a signed 8-bit number. See _div16 (Divide, 16 Bit); _div16s (Divide Signed, 16
Bit); and _div8s (Divide Signed, 8 Bit).
The DIV instruction applies to Series 5000 and 6000 devices.
Syntax:
The DIV instruction requires no operands:
DIV
Table 29 describes the attributes of the DIV instruction.
Table 29. DIV Instruction
Instruction Hexadecimal
Opcode
Instruction
Size (Bytes)
CPU Cycles
Required
Affect on
Carry Flag
DIV ED 1 14 None
Example:
The following example performs the division 7/3. Before the DIV instruction
executes, TOS contains 7 and NEXT contains 3. After the DIV instruction
executes, TOS contains 2 (7/3 = 2, with remainder) and NEXT contains 1 (the
remainder).
pushs #3 ; (3, -, -)
pushs #7 ; (7, 3, -)
div ; (2, 1, -)
Neuron Assembly Language Reference 85