UPD78F0078GK-9ET-A Renesas Electronics America, UPD78F0078GK-9ET-A Datasheet - Page 414

• Manufacturer Part Number: UPD78F0078GK-9ET-A
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0078GK-9ET-A

• Lead Free Status / Rohs Status: Supplier Unconfirmed

19.4.3 Software interrupt request acknowledgment operation
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.
412
CPU processing
CPU processing
Remark 1 clock: 1/f
Remark 1 clock: 1/f
A software interrupt request is acknowledged by BRK instruction execution. Software interrupts cannot be disabled.
If a software interrupt request is acknowledged, the contents are saved into the stacks in the order of the program
Return from a software interrupt is possible with the RETB instruction.
Caution
(
(
(
(
PR = 1)
PR = 0)
PR = 1)
PR = 0)
IF
IF
IF
IF
Do not use the RETI instruction for returning from a software interrupt.
Figure 19-12. Interrupt Request Acknowledgment Timing (Maximum Time)
Figure 19-11. Interrupt Request Acknowledgment Timing (Minimum Time)
CPU
CPU
(f
(f
Instruction
Instruction
CPU
CPU
: CPU clock)
: CPU clock)
CHAPTER 19 INTERRUPT FUNCTIONS
User’s Manual U14260EJ4V0UD
Divide instruction
Instruction
25 clocks
33 clocks
32 clocks
8 clocks
PSW and PC save,
jump to interrupt
servicing
PSW and PC save,
jump to interrupt
servicing
7 clocks
6 clocks
6 clocks
Interrupt servicing
program
Interrupt servicing
program