DL205 User Manual, 4th Edition, Rev. D
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Chapter 5: Standard RLL Instructions
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Subtract Binary Top of Stack (SUBBS)
Subtract Binary Top of Stack is a 32-bit instruction that
subtracts the binary value in the first level of the accumulator
stack from the binary value in the accumulator. The result
resides in the accumulator. The value in the first level of
the accumulator stack is removed, and all stack locations are
moved up one level.
NOTE: Status flags are valid only until another instruction uses the same flag.
In the following example, when X1 is on, the value in V1400 and V1401 will be loaded into
the accumulator using the Load Double instruction. The value in V1420 and V1421 is loaded
into the accumulator using the Load Double instruction, pushing the value previously loaded
in the accumulator onto the accumulator stack. The binary value in the first level of the
accumulator stack is subtracted from the binary value in the accumulator using the Subtract
Stack instruction. The value in the accumulator is copied to V1500 and V1501 using the Out
Double instruction.
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SUBBS
Discrete Bit Flags Description
SP63 On when the result of the instruction causes the value in the accumulator to be zero
SP64 On when the 16-bit subtraction instruction results in a borrow
SP65 On when the 32-bit subtraction instruction results in a borrow
SP70 On anytime the value in the accumulator is negative
LDD
V1400
X1
Load thevalue in V1400 and
V1401 into theaccumulator
LDD
V1420
Load thevalue in V1420 and
V1421 into theaccumulator
OUTD
V1500
Copy thevalue in the
accumulatortoV1500
and V1501
X XXX
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