UPD78F9234MC-5A4-A Datasheet, PDF (227/419 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 13 INTERRUPT FUNCTIONS
13.1 Interrupt Function Types
There are two types of interrupts: maskable interrupts and resets.
• Maskable interrupts
These interrupts undergo mask control. When an interrupt request occurs, the standby release signal occurs,
and if an interrupt can be acknowledged then the program corresponding to the address written in the vector
table address is executed (vector interrupt servicing). When several interrupt requests are generated at the
same time, processing takes place in the priority order of the vector interrupt servicing. For details on the
priority order, see Table 13-1.
There are nine internal sources and four external sources of maskable interrupts.
• Reset
The CPU and SFR are returned to their initial states by the reset signal. The causes for reset signal
occurrences are shown in Table 13-1.
When a reset signal occurs, program execution starts from the programs at the addresses written in addresses
0000H and 0001H.
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