Section 10 Interrupt Controller (INTC)
Rev.1.00 Dec. 13, 2005 Page 308 of 1286
REJ09B0158-0100
10.5 Operation
10.5.1 Interrupt
Sequence
The sequence of interrupt operations is described below. Figure 10.4 is the flowchart of the
operations.
1. Interrupt request sources send interrupt request signals to the INTC.
2. The INTC selects the interrupt with the highest-priority among the interrupts that have been
sent, according to the priority levels set in INTPRI and INT2PRI0 to INT2PRI7. Lower-
priority interrupts are held as pending interrupts. If two of the interrupts have the same priority
level or multiple interrupts are generated by a single module, the interrupt with the highest
priority is selected according to table 10.12.
3. The priority level of the interrupt selected by the INTC is compared with the interrupt mask
level (IMASK) set in SR of the CPU. If the priority level is higher than the mask level, the
INTC accepts the interrupt and sends an interrupt request signal to the CPU.
4. The CPU accepts an interrupt at the next break between instructions.
5. The interrupt source code is set in the interrupt event register (INTEVT).
6. The SR and program counter (PC) are saved in SSR and SPC, respectively. At the same time,
R15 is saved in SGR.
7. The BL, MD, and RB bits in SR are set to 1.
8. Execution jumps to the start address of the interrupt exception handling routine (the sum of the
value set in the vector base register (VBR) and H'0000 0600).
In the exception handling routine, branching with the INTEVT value as an offset provides a
convenient way to differentiate between the interrupt sources. Execution thus branches to the
handling routines for the individual interrupt sources.
Notes: 1. When the INTMU bit in the CPU operating mode register (CPUOPM) is set to 1, the
interrupt mask level (IMASK) in SR is automatically set to the level of the accepted
interrupt. When the INTMU bit is cleared to 0, the IMASK value in SR is not affected
by the accepted interrupt.
2. The interrupt source flag should be cleared in the interrupt handling routine. To ensure
that an interrupt source which should have been cleared is not inadvertently accepted
again, read the interrupt source flag after it has been cleared, wait for the time shown in
table 10.8, and then clear the BL bit or execute an RTE instruction.
3. The power-on reset initializes the values of the interrupt mask bits for IRQ interrupts,
IRL interrupts, and interrupts for the on-chip modules. Thus, INTMSKCLR must be
used to clear the interrupt mask setting (INTMSK) for any required IRQ, IRL, and on-
chip module interrupts .
Summary of Contents for SH7780 Series
Page 2: ...Rev 1 00 Dec 13 2005 Page ii of l ...
Page 28: ...Rev 1 00 Dec 13 2005 Page xxviii of l ...
Page 50: ...Rev 1 00 Dec 13 2005 Page l of l ...
Page 82: ...Section 1 Overview Rev 1 00 Dec 13 2005 Page 32 of 1286 REJ09B0158 0100 ...
Page 122: ...Section 3 Instruction Set Rev 1 00 Dec 13 2005 Page 72 of 1286 REJ09B0158 0100 ...
Page 146: ...Section 4 Pipelining Rev 1 00 Dec 13 2005 Page 96 of 1286 REJ09B0158 0100 ...
Page 196: ...Section 6 Floating Point Unit FPU Rev 1 00 Dec 13 2005 Page 146 of 1286 REJ09B0158 0100 ...
Page 292: ...Section 9 L Memory Rev 1 00 Dec 13 2005 Page 242 of 1286 REJ09B0158 0100 ...
Page 492: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Dec 13 2005 Page 442 of 1286 REJ09B0158 0100 ...
Page 674: ...Section 15 Clock Pulse Generator CPG Rev 1 00 Dec 13 2005 Page 624 of 1286 REJ09B0158 0100 ...
Page 692: ...Section 16 Watchdog Timer and Reset Rev 1 00 Dec 13 2005 Page 642 of 1286 REJ09B0158 0100 ...
Page 726: ...Section 18 Timer Unit TMU Rev 1 00 Dec 13 2005 Page 676 of 1286 REJ09B0158 0100 ...
Page 1032: ...Section 25 Audio Codec Interface HAC Rev 1 00 Dec 13 2005 Page 982 of 1286 REJ09B0158 0100 ...
Page 1150: ...Section 28 General Purpose I O GPIO Rev 1 00 Dec 13 2005 Page 1100 of 1286 REJ09B0158 0100 ...
Page 1184: ...Section 29 User Break Controller UBC Rev 1 00 Dec 13 2005 Page 1134 of 1286 REJ09B0158 0100 ...
Page 1266: ...Section 31 Electrical Characteristics Rev 1 00 Dec 13 2005 Page 1216 of 1286 REJ09B0158 0100 ...
Page 1328: ...Appendix Rev 1 00 Dec 13 2005 Page 1278 of 1286 REJ09B0158 0100 ...
Page 1336: ...Rev 1 00 Dec 13 2005 Page 1286 of 1286 REJ09B0158 0100 ...
Page 1339: ......
Page 1340: ...SH7780 Hardware Manual ...