R01UH0823EJ0100 Rev.1.00
Page 266 of 1823
Jul 31, 2019
RX23W Group
14. Exception Handling
14.5.6
Non-Maskable Interrupt
1. The value of the processor status word (PSW) is saved on the stack (ISP).
2. The processor mode select bit (PM), the stack pointer select bit (U), and the interrupt enable bit (I) in PSW are
cleared to 0.
3. If the interrupt was generated during the execution of an RMPA, SCMPU, SMOVB, SMOVF, SMOVU, SSTR,
SUNTIL, or SWHILE instruction, the value of the program counter (PC) for that instruction is saved on the stack
(ISP). For other instructions, the PC value of the next instruction is saved.
4. The processor interrupt priority level bits (IPL[3:0]) in PSW are set to Fh.
5. The vector is fetched from the value of EXTB + address 0000 0078h.
6. The fetched vector is set to the PC and processing branches to the exception handling routine.
14.5.7
Interrupt
1. The value of the processor status word (PSW) is saved on the stack (ISP) or, for the fast interrupt, in the backup
PSW (BPSW).
2. The processor mode select bit (PM), the stack pointer select bit (U), and the interrupt enable bit (I) in PSW are
cleared to 0.
3. If the interrupt was generated during the execution of an RMPA, SCMPU, SMOVB, SMOVF, SMOVU, SSTR,
SUNTIL, or SWHILE instruction, the value of the program counter (PC) for that instruction is saved. For other
instructions, the PC value of the next instruction is saved. Saving of the PC is in the backup PC (BPC) for fast
interrupts.
4. The processor interrupt priority level bits (IPL[3:0]) in PSW indicate the interrupt priority level of the interrupt.
5. The vector for an interrupt source other than the fast interrupt is fetched from the interrupt vector table. For the fast
interrupt, the address is fetched from the fast interrupt vector register (FINTV).
6. The fetched vector is set to the PC and processing branches to the exception handling routine.
14.5.8
Unconditional Trap
1. The value in the processor status word (PSW) is saved on the stack (ISP).
2. The processor mode select bit (PM), the stack pointer select bit (U), and the interrupt enable bit (I) in PSW are
cleared to 0.
3. The value of the program counter (PC) for the next instruction is saved on the stack (ISP).
4. For the INT instruction, the value at the vector corresponding to the INT instruction number is fetched from the
interrupt vector table.
For the BRK instruction, the value at the vector from the start address is fetched from the interrupt vector table.
5. The fetched vector is set to the PC and processing branches to the exception handling routine.