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14 e, f index registers, E, f index registers -51 – Delta DVP-ES2 User Manual

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2 . P r o g r a m m i n g C o n c e p ts

2.14 E, F Index Registers

Index registers are used as modifiers to indicate a specified device (word, double word) by defining

an offset. Devices can be modified includes byte device (KnX, KnY, KnM, KnS, T, C, D) and bit

device (X, Y, M, S). E, F registers cannot be used for modifying constant (K, H) Index registers not

used as a modifier can be used as general purpose register.

Index register [E], [F]

Index registers are 16-bit registers which can be read and written. There are 16 points indicated as

E0~E7 and F0~F7. If you need a 32-bit register, you have to designate E. In this case, F will be

covered up by E and cannot be used. It is recommended to use instruction DMOVP K0 E to reset E

(including F) at power-on.

F0

E0

E0

F0

16-bit

16-bit

32-bit

Low word

High word

The combinations of E and F when designating a 32-bit register are:

(E0, F0) , (E1, F1) (E2, F2) (E3, F3) (E4, F4) , (E5, F5) (E6, F6) (E7, F7)

Example:

When X0 = ON and E0 = 8, F0 = 14, D5E0 = D(5+8) = D13, D10F0 = D(10+14) = D24, the content

in D13 will be moved to D24.

K14

F0

X0

K8

E0

MOV

D5E0

D10F0

MOV

MOV

2.15 Nest Level Pointer[N], Pointer[P], Interrupt Pointer [I]

The control point of
master control nested

N

Master control nested

N0~N7, 8 points

Pointer

The location point of CJ,
CALL

P

For CJ, CALL instructions

P0~P255, 256 points

2 - 5 1

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