NEC PD75P402 Manuale Utente

On the 

µ

PD75402A there are 3 vectored interrupt sources and one testable input, enabling a wide variety of

applications to be handled.

Moreover, the 

µ

PD75402A’s interrupt control circuit has the following special features, making possible

extremely fast interrupt servicing.

(a)

Acknowledgment enabling/disabling is possible by means of the interrupt master enable flag (IME) and

the interrupt enable flag (IE

×××

).

(b) Any desired interrupt service start address can be set using the vector table (for rapid starting of the actual

interrupt service program).

(c)

Interrupt request flag (IRQ

×××

) can be tested and cleared (allowing checking of interrupt generation by

software).

(d) Standby mode (HALT) can be released by an interrupt request (release source is selectable from other than

INT0 by means of interrupt enable flag).

The interrupt control circuit is configured as shown in Fig. 6-1, with each hardware item mapped onto data

memory space.