NEC PD75P402 Manual do Utilizador descarregar pdf (Página 145)

134

CHAPTER 6. INTERRUPT FUNCTIONS

6.4 INTERRUPT SEQUENCE

When an interrupt is generated, it is serviced by the procedure shown in Fig. 6-8.

Fig. 6-8 Interrupt Servicing Procedure

Interrupt (INT×××) generation

IExxx set?

IRQxxx set

YES

Corresponding VRQn

generation

YES

IST0=0

IME=1

Save PC and PSW contents to stack memory; place data in vector table corresponding

to initiated VRQn into PC.

Change IST0 contents to 1

Reset (0) acknowledged IRQxxx

Branch to start address of interrupt service program proccessing

Hold pending until

IExxx is set

Hold pending

until IME is set

Hold pending until

end of processing

in execution

1 2 ... 140 141 142 143 144 145 146 147 148 149 150 ... 194 195

Sem comentários

NEC PD75P402 Manual do Utilizador Página 145