UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 537

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

20.2 INTERRUPT PROCESSING MODES
20.2.1 Vectored Interrupt Processing
to the stack, a branch is made to the address indicated by the data stored in the vector table, and the interrupt processing
routine is executed.
20.2.2 Macro Service
hardware. Since macro service is performed without the intermediation of the CPU, it is not necessary to save or restore
CPU statuses such as the program counter (PC) and program status word (PSW) contents. This is therefore very effective
in improving the CPU service time (See 20.8 Macro Service Function).
20.2.3 Context Switching
set vector address in the register bank, and at the same time the current program counter (PC) and program status word
(PSW) are saved in the register bank (see 20.4.2 BRKCS Instruction Software Interrupt (Software Context Switching)
Acknowledgment Operation and 20.7.2 Context Switching).
There are three PD784026 interrupt processing modes, as follows:
• Vectored interrupt processing
• Macro service
• Context switching
When an interrupt is acknowledged, the program counter (PC) and program status word (PSW) are automatically saved
When an interrupt is acknowledged, CPU execution is temporarily suspended and a data transfer is performed by
When an interrupt is acknowledged, the prescribed register bank is selected by hardware, a branch is made to a pre-
Remark “Context” refers to the CPU registers that can be accessed by a program while that program is being executed.
These registers include general registers, the program counter (PC), program status word (PSW), and stack
pointer (SP).
CHAPTER 20 INTERRUPT FUNCTIONS
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