User data – Toshiba T2N User Manual

Page 197

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3. User Data

184

PROSEC T2N

Example 3) Substituting the result of an operation in an index register

–[

RW200 - 30

I

]–

(Substitute the result of subtracting 30 from RW200 in I)

–[

XW004 ENC (4) J

]–

(Substitute the uppermost ON bit position of XW004 in J (encode))

Although, basically, index registers are processed as single-length
(16 bits), when, for instance, using an index register as the storage
destination for a instruction which becomes double-length as the
result of a multiplication instruction or the like, only the combinations
J•I or K•J are effective. In this case, it becomes J•I by designating I in
the double-length operand position, and J becomes upper while I
becomes lower. In the same, by designating J, it becomes K•J, and K
becomes upper while J becomes lower.
Example)

–[

D1357 * 10

J • I ]

The following are examples of registers in which index modification has
been executed.

When I = 0,

expresses RW100

When I = 1,

expresses RW101

When I = -1,

expresses RW099

When I = 100,

expresses RW200

When I = -100,

expresses RW000

When J = 0,

expresses D0201 · D0200

When J = 1,

expresses D0202 · D0201

When J = 2,

expresses D0203 · D0202

When J = -1,

expresses D0200 · D0199

When J = -2,

expresses D0199 · D0198

I

RW100

J

D0201

·

D0200

NOTE

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