upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 328

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

15.4.2 Software interrupt request acknowledgment
disabled.
status word (PSW), then program counter (PC), the IE flag is reset (0), and the contents of the vector table (003EH,
003FH) are loaded into the PC and branched.
328
CPU processing
CPU processing
Remark 1 clock: 1/f
Remark 1 clock: 1/f
A software interrupt request is acknowledged by BRK instruction execution.
If a software interrupt request is acknowledged, the contents are saved into the stacks in the order of the program
Restoring from a software interrupt is possible by using the RETB instruction.
Caution Do not use the RETI instruction for restoring from the software interrupt.
(
(
(
(
PR = 1)
PR = 0)
PR = 1)
PR = 0)
IF
IF
IF
IF
Figure 15-9. Interrupt Request Acknowledgment Timing (Maximum Time)
Figure 15-8. Interrupt Request Acknowledgment Timing (Minimum Time)
CPU
CPU
(f
(f
Instruction
Instruction
CPU
CPU
: CPU clock)
: CPU clock)
CHAPTER 15 INTERRUPT FUNCTIONS
User’s Manual U16961EJ4V0UD
Divide instruction
Instruction
25 clocks
33 clocks
32 clocks
8 clocks
PSW and PC saved,
jump to interrupt
servicing
PSW and PC saved,
jump to interrupt
servicing
7 clocks
Software interrupts cannot be
6 clocks
6 clocks
Interrupt servicing
program
Interrupt servicing
program