1989_MELPS_7700_Software_Manual

DIV Divide DIV
Operation
B(remainder}, A(quotient} ~ (B, A) / M
If m=O
B A M(n+1} M(n} A B
Dividend + ! Divisor ! ~ Quotient Remainder
If m=1
BL
AL
Dividend + I Quotient I ! Remainder!
Description
When the data length selection flag m is set to 0, a 32-bit data stored in the
accumulators B (upper 16 bits) and A (lower 16 bits) are divided by a 16-bit data
in memory. The quotient is placed in the accumulator A, and the remainder is
placed in the accumulator B.
When the data length selection flag m is set to 1, a 16-bit data stored in the lower
8 bits of the accumulators B (upper 8 bits) and A (lower 8 bits) are divided by an
8 bit data in memory. The quotient is placed in the lower 8 bits of the
accumulator A, and the remainder is placed in the lower 8 bits of the accumulator
B.
When an overflow results from this operation negrect removed out, the V flag is
set.
When divisor is 0, the zero division interrupt is generated, in which case the
contents of the processor status register are saved on the stack and a branch
occurs to the address in bank-O as specified by the zero division interrupt vector.
Accumulator contents are not changed.
Status flags
IPL
N
v
m
x
D
I
Z
c
Not affected.
Set to 1 when bit 15 (or bit 7 if the data length selection flag m is set to 1) of
quotient from the operation is 1. Otherwise, cleared to O.
Set to 1 when the quotient from the operation exceeds 16 bits (or 8 bits if the data
length selection flag m is set to 1) (I.e., an overflow has occurred). Otherwise,
cleared to O. No changes occur when divisor is O.
Not affected.
Not affected.
Not affected.
Not affected.
Set to 1 when the quotient from the operation is O. Otherwise, cleared to O. No
changes occur when divisor is O.
Set to 1 when the quotient from the operation exceeds 16 bits (or 8 bits if the data
length selection flag m is set to 1) (I.e., an overflow has occurred). Otherwise,
cleared to O. No changes occur when divisor is O.
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