175
The mantissa is expressed as a value less than one, i.e., to seven decimal
places.
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
First word
Exponent (0 to 7)
Sign of exponent 0: +
1: –
1010000100010001
Mantissa (leftmost 3 digits)
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Second word
Mantissa (leftmost 4 digits)
0001000100010001
= 0.1111111 x 10
–2
Flags ER: Dr and Dr+1 contain 0.
Dd, Dd+1, Dr, or Dr+1 is not BCD.
The result is not between 0.0000001 x 10
–7
and 0.999999 x 10
+7
.
Indirectly addressed DM word is non-existent. (Content of *DM word
is not BCD, or the DM area boundary has been exceeded.)
EQ: ON when the result is 0.
The following example shows how to divide two whole four-digit numbers
(i.e., numbers without fractions) so that a floating-point value can be ob-
tained.
First the original numbers must be placed in floating-point form. Because the
numbers are originally without decimal points, the exponent will be 4 (e.g.,
3452 would equal 0.3452 x 10
4
). All of the moves are to place the proper
data into consecutive words for the final division, including the exponent and
zeros. Data movements for Dd and Dd+1 are shown at the right below.
Movements for Dr and Dr+1 are basically the same.The original values to be
divided are in DM 0000 and DM 0001. The final division is also shown.
Example
BCD Calculations Section 5-17
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