upd17240 Renesas Electronics Corporation., upd17240 Datasheet - Page 66

• Manufacturer Part Number: upd17240
• Description: 4-bit Single-chip Microcontrollers For Small General-purpose Infrared Remote Control Transmitters
• Manufacturer: Renesas Electronics Corporation.

8.3
the instruction executed when the IRQ×× flag was set has ended. Since the MOVT instruction, EI instruction, and
the instruction that matches the condition to skip use two instruction cycles, the interrupt enabled while this instruction
is executed is processed after the second instruction cycle is over.
set.
highest priority. The interrupt with the lower priority is held pending until the processing of the interrupt with the higher
priority is finished.
8.3.1
66
If the IRQ×× flag is set to 1 when the IP×× flag is “1”, interrupt processing is started after the instruction cycle of
If the IP×× flag is “0”, the interrupt processing is not performed even if the IRQ×× flag is set, until the IP×× flag is
If two or more interrupts are enabled simultaneously, the interrupts are processed starting from the one with the
When an interrupt has been acknowledged, the CPU performs processing in the following sequence:
One instruction cycle is required to perform the above processing.
Interrupt Sequence
Operations when interrupt is acknowledged
µ PD17240, 17241, 17242, 17243, 17244, 17245, 17246
Save contents of PSWORD to interrupt stack register
Loads vector address to program counter
Decrements value of stack pointer by 1
Clears IRQ××× corresponding to
INTE flag and acknowledged interrupt
Saves contents of program counter to
stack addressed by stack pointer
Data Sheet U15002EJ1V1DS
(SP − 1)