number of digits allowed is recognized as a decimal
divide exception. The operation is suppressed, and a
program interruption occurs. Divisor and dividend re
main unchanged in their storage locations.
The divisor and dividend fields may overlap only if
their
Addressing
Protection
Specification
Data
Decimal divide
Programming Note
The maximum dividend size is 31 digits and sign.
Since the smallest remainder size is one digit and sign,
the maximum quotient size is 29 digits and sign.
The condition for a divide exception can be deter
mined by a trial subtraction. The leftmost digit of the
divisor field is aligned with the leftmost-less-one digit
of the dividend field. When the divisor, so aligned, is
less than or equal to the dividend, a divide exception
is indicated.
A decimal-divide exception occurs if the dividend
does not have at least one leading zero.
Pack
PACK
7 8 11 12 1516
The format of the second operand is changed from
zoned to packed, and the result is placed in the first
operand location.
The second operand is assumed to have the zoned
format. All zones are ignored, except the zone over the
low-order digit, which is assumed to represent a sign.
The sign is placed in the right four bits of the low
order byte, and the digits are placed adjacent to the
sign and to each other in the remainder of the result
field.
first operand field and are not checked for valid codes.
The fields are processed right to left. If necessary,
the second operand is extended with high-order zerO's.
If the first operand field is too short to contain all
significant digits of the second operand field, the re
maining digits are ignored.
occur and are processed by storing each result byte
immediately after the necessary operand bytes are
fetched.
38
Condition Code: The code remains unchanged.
Protection
Addressing
Unpack
UNPK
7 8 11 12 1516
The format of the second operand is changed from
packed to zoned, and the result is placed in the first
aperand lacation.
The digits and sign of the packed operand are
placed unchanged in the first operand location, using
the zoned format. Zones with coding 1111 in the bin
aJ'y-coded-decimal mode and coding
byte, which receives the sign of the packed operand.
The operand sign and digits are not checked for valid
codes.
The fields are processed right to left. The second
operand is extended with zero digits before unpack
ing, if necessary. If the first operand field is too short
to contain all significant digits of the second operand,
the remaining digits are ignored. The first and second
operand fields may overlap and are processed by stor
ing a result byte immediately after the necessary op
erand bytes are fetched.
Condition Code: The code remains unchanged.
Addressing
Protection
Move with Offset
The second operand is placed to the left of and ad
jacent to the low-order four bits of the first operand.
The low-order four bits of the first operand are at
tached as low-order bits to the second operand, the
second operand bits are offset by four bit positions,
and the result is placed in the first operand location.
The first and second operand bytes are not checked
for valid codes.
The fields are processed right to left. If necessary,
the second operand is extended with high-order