NEC PD754144 - Manual (Page 186)

186
User’s Manual U10676EJ3V0UM
CHAPTER 7 INTERRUPT AND TEST FUNCTIONS
The
µPD754244 has six vectored interrupt sources and one test input that can be used for various applications.
The interrupt controller of the µPD754244 has unique features and can service interrupts at extremely high speed.
(1) Interrupt function
(a) Hardware-controlled vectored interrupt functions that can control acknowledgment of an interrupt by using
an interrupt enable flag (IE
×××) and interrupt master enable flag (IME)
(b) Any interrupt start address can be set.
(c) Interrupt nesting function that can specify priority by using an interrupt priority select register (IPS)
(d) Test function of interrupt request flag (IRQ ×××) (Occurrence of an interrupt can be checked by software.)
(e) Releases standby mode (The interrupt that is used to release the standby mode can be selected by the
interrupt enable flag.)
(2) Test function
(a) Checks setting of a test request flag (IRQ2) via software
(b) Releases standby mode (The test source that releases the standby mode can be selected by the test
enable flag.)
7.1 Configuration of Interrupt Controller
The interrupt controller is configured as shown in Figure 7-1, and each hardware unit is mapped to the data memory
space.