228
Flags ER: Indirectly
addressed
DM word is non-existent. (Content of
:
DM word is
not BCD, or the DM area boundary has been exceeded.)
CY: ON when the result is negative, i.e., when Mi is less than Su plus CY.
EQ: ON when the result is 0.
OF: ON when the result exceeds +2,147,483,647 (7FFF FFFF).
UF: ON when the result is below –2,147,483,648 (8000 0000).
Example 1: Normal Data In
this example, the eight-digit number in IR 002 and IR 001 is subtracted from
the
eight-digit number in DM 0021 and DM 0020, and the result is output
to LR 22
and LR 21. If the result is negative, CY (SR 25504) is turned ON.
CLC(41)
00000
SBBL(––)
001
DM 0020
LR 21
Address Instruction Operands
00000 LD 00000
00001 CLC(41)
00002 SBBL(––)
001
DM 0020
LR 21
14020187
+ 00A3F8C5 = 14A5F
A4C
Au + 1 : 002
Au : 001
Ad + 1 : DM 0021
Ad : DM 0020
1402 0187
00A3
F8C5
0
R
+ 1 : LR 22
R : LR 21
08C2135E
0
CY (Cleared with CLC(41))
CY (No carry)
–
Note The
status of the UF and
OF flags can be ignored since they are relevant only in
the subtraction of signed binary data.
In
the following example, SBBL(––) is
used to subtract one 32-bit signed binary
value from another and output the 32-bit signed binary result to R and R+1.
The effective range for 32-bit signed binary values is –2,147,483,648
(8000 0000)
to +2,147,483,647 (7FFF FFFF). The
overflow flag (OF: SR 25404)
is
turned
ON if the result exceeds +2,147,483,647 (7FFF FFFF) and the under
-
flow
flag (UF: SR 25405) is turned ON is the result falls below –2,147,483,648
(8000 0000).
CLC(41)
00000
SBBL(––)
001
DM 0020
LR 21
Address Instruction Operands
00000 LD 00000
00001 CLC(41)
00002 SBBL(––)
001
DM 0020
LR 21
Example 2:
Signed Binary Data
Binary Calculations Section 5-20
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