uPD789074 Subseries 8-Bit Single-Chip Microcontrollers UD - Home

CHAPTER 10 INTERRUPT FUNCTIONS10.1 Interrupt Function TypesThe following two types of interrupt functions are used.(1) Non-maskable interruptThis interrupt is acknowledged unconditionally even if interrupts are disabled. It does not undergo interruptpriority control and is given top priority over all other interrupt requests.A standby release signal is generated.An interrupt from the watchdog timer is the only non-maskable interrupt source.(2) Maskable interruptThese interrupts undergo mask control. If two or more interrupts are simultaneously generated, eachinterrupt has a predetermined priority as shown in Table 10-1.A standby release signal is generated.There are three external sources and five internal sources of maskable interrupts.10.2 Interrupt Sources and ConfigurationThere are a total of 9 non-maskable and maskable interrupt sources (see Table 10-1).150User’s Manual U14801EJ3V1UD