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EMIND
MIN ((D), (M : M + 1)) ⇒ D
Operation:
Description:
Subtracts an unsigned 16-bit value in memory from an unsigned 16-bit
value in double accumulator D to determine which is larger, and leaves
the smaller of the two values in D. The Z status bit is set when the result
of the subtraction is zero (the values are equal), and the C status bit is
set when the subtraction requires a borrow (the value in memory is larger
than the value in the accumulator). When C = 0, the value in D has been
replaced by the value in memory.
The unsigned value in memory is accessed by means of indexed ad-
dressing modes, which allow a great deal of flexibility in specifying the
address of the operand. Auto increment/decrement variations of indexed
addressing facilitate finding the largest value in a list of values.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Condition codes reflect internal subtraction (R = D – M : M + 1).
Addressing Modes, Machine Code, and Execution Times:
Source Form
EMIND oprx0_xysp
EMIND oprx9,xysp
EMIND oprx16,xysp
EMIND [D ,xysp ]
EMIND [ oprx16,xysp ]
CPU12
REFERENCE MANUAL
Place Smaller of Two
Unsigned 16-Bit Values
in Accumulator D
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $0000; cleared otherwise.
D15 • M15 • R15 + D15 • M15 • R15
Set if a two's complement overflow resulted from the operation;
cleared otherwise.
D15 • M15 + M15 • R15 + R15 • D15
Set if the value of the content of memory is larger than the value of
the accumulator; cleared otherwise.
Address Mode
IDX
IDX1
IDX2
[D,IDX]
[IDX2]
INSTRUCTION GLOSSARY
V
C
∆
∆
Object Code
18 1B xb
18 1B xb ff
18 1B xb ee ff
18 1B xb
18 1B xb ee ff
EMIND
Cycles
Access Detail
4
ORfP
4
ORPO
5
OfRPP
7
OfIfRfP
7
OfIPRfP
MOTOROLA
6-83
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