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Chapter 12 interrupt functions – NEC PD78214 User Manual

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Chapter 12 Interrupt Functions

12

(2) Macro service channel configuration

The macro service pointer (MP) indicates a data buffer area in the 64K memory space as a transfer source or
destination.

The SFR pointer (SFRP) is set with the lower 8 bits of the address of an SFR used as a transfer source or
destination.

The macro service counter (MSC) specifies the number of data transfers to be performed.

The macro service channel, which holds the macro service pointer, SFR pointer, and macro service counter,
is located at addresses 0FE00H through 0FEFFH in the internal RAM space.

The channel pointer indicates the macro service channel, as shown in Fig. 12-22. The channel pointer holds
the lower 8-bits of the address.

Caution The following registers cannot be used as SFRs.

IF0L, IF0H, MK0L, MK0H, PR0L, PR0H, ISM0L, ISM0H, and IST

Fig. 12-22 Type B Macro Service Channel

Macro service counter

(MSC)

SFR pointer

(SFRP)

Macro service pointer,

low (MPL)

Macro service pointer,

high (MPH)

Mode register

Channel pointer

SFR

Buffer area

64K memory space

Higher address

Lower address

(Macro service buffer address) = (Macro service pointer)

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