UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 536

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

20.1.1 Software Interrupts
which performs context switching.
20.1.2 Operand Error Interrupts
instruction, and LOCATION instruction.
20.1.3 Non-Maskable Interrupts
to interrupt priority control, and are of higher priority that any other interrupt.
20.1.4 Maskable Interrupts
acknowledgment enabling/disabling can be specified for all maskable interrupts by means of the IE flag in the program status
word (PSW).
service (though some interrupts cannot use macro service: see Table 20-2).
simultaneously is predetermined (default priority) as shown in Table 20-2. Also, multiprocessing control can be performed
with interrupt priorities divided into 4 levels. However, macro service requests are acknowledged without regard to priority
control or the IE flag.
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Interrupts by software consist of the BRK instruction which generates a vectored interrupt and the BRKCS instruction
Software interrupts are acknowledged even in the interrupt disabled state, and are not subject to priority control.
These interrupts are generated if there is an illegal operand in an MOV STBC, #byte instruction or MOV WDMC, #byte
Operand error interrupts are acknowledged even in the interrupt disabled state, and are not subject to priority control.
A non-maskable interrupt is generated by NMI pin input or the watchdog timer.
Non-maskable interrupts are acknowledged unconditionally*, even in the interrupt disabled state. They are not subject
* Except during execution of the service program for the same non-maskable interrupt, and during execution of the
A maskable interrupt is one subject to masking control according to the setting of an interrupt mask flag. In addition,
In addition to normal vectored interrupt, maskable interrupts can be acknowledged by context switching and macro
The priority order for maskable interrupt requests when interrupt requests of the same priority are generated
service program for a higher-priority non-maskable interrupt
CHAPTER 20 INTERRUPT FUNCTIONS