9.1.6
Interrupts ................................................................................................................................................ 204
9.1.7
Unconditional Trap ................................................................................................................................ 204
9.2
Exception Handling Procedure........................................................................................................................ 205
9.3
Acceptance of Exceptions ............................................................................................................................... 207
9.3.1
Timing of Acceptance and Saved PC Values ......................................................................................... 207
9.3.2
Vector and Site for Saving the Values in the PC and PSW .................................................................... 208
9.4
Hardware Processing for Accepting and Returning from Exceptions ............................................................. 209
9.5
Hardware Pre-Processing ................................................................................................................................ 210
9.5.1
Undefined Instruction Exception ........................................................................................................... 210
9.5.2
Privileged Instruction Exception ............................................................................................................ 210
9.5.3
Floating-Point Exceptions ...................................................................................................................... 210
9.5.4
Reset ....................................................................................................................................................... 210
9.5.5
Non-Maskable Interrupt ......................................................................................................................... 211
9.5.6
Interrupts ................................................................................................................................................ 211
9.5.7
Unconditional Trap ................................................................................................................................ 211
9.6
Return from Exception Handling Routines ..................................................................................................... 212
9.7
Order of Priority for Exceptions ...................................................................................................................... 212
10.
Interrupt Control Unit (ICU) ....................................................................................................................... 213
10.1
Overview ......................................................................................................................................................... 213
10.2
Register Descriptions ...................................................................................................................................... 215
10.2.1
Interrupt Request Register i (IRi) (i = interrupt vector number) ............................................................ 223
10.2.2
Interrupt Request Destination Setting Register i (ISELRi) (i = interrupt vector number) ...................... 225
10.2.3
Interrupt Request Enable Register m (IERi) (i = 02h to 1Fh) ................................................................ 226
10.2.4
Interrupt Priority Register i (IPRi) (i = 00h to 8Fh) ............................................................................... 227
10.2.5
Fast Interrupt Register (FIR) .................................................................................................................. 228
10.2.6
IRQ Detection Enable Register n (IRQERn) (n = 0 to 15) ..................................................................... 229
10.2.7
IRQ Control Register n (IRQCRn) (n = 0 to 15) .................................................................................... 230
10.2.8
Non-maskable Interrupt Enable Register (NMIER) ............................................................................... 231
10.2.9
NMI Pin Interrupt Control Register (NMICR) ....................................................................................... 232
10.2.10
Non-maskable Interrupt Status Register (NMISR) ................................................................................ 233
10.2.11
Non-maskable Interrupt Clear Register (NMICLR) ............................................................................... 234
10.2.12
Software Standby Release IRQ Enable Register (SSIER) ..................................................................... 235
10.3
Vector Table .................................................................................................................................................... 236
10.3.1
Interrupt Vector Table ............................................................................................................................ 236
10.3.2
Fast Interrupt Vector Address ................................................................................................................ 241
10.3.3
Non-maskable Interrupt Vector Address ................................................................................................ 241
10.4
Operation ......................................................................................................................................................... 242
10.4.1
Enabling and Disabling Interrupts .......................................................................................................... 242
10.4.2
Interrupt Status Flag ............................................................................................................................... 243