Section 10 Interrupt Controller (INTC)
Rev.1.00 Dec. 13, 2005 Page 312 of 1286
REJ09B0158-0100
10.7 Usage
Notes
10.7.1
To Clear Interrupt Request When Holding Function Selected
When an IRQ level-sense interrupt request or IRL level-encoded interrupt request (IRQ/IRL level
interrupt request) is generated and the holding function is in use, the interrupt request must be
cleared in the interrupt handling routine after it has been accepted. Figure 10.5 shows an example
of an interrupt-handling routine to clear interrupt request holding in the detection circuit.
Interrupt handling
Instruct the external device to cancel
the IRQ/IRL level interrupt request by
using the GPIO output or writing to an
address in the local bus
Allow time for the cancellation of
external device interrupt requests and
for the INTC to respond to
cancellation requests
Clear the IRQ/IRL level interrupt
request holding in the detection circuit
and clear the IRQ interrupt source
End of IRQ/IRL level
interrupt handling
1) Writing to the GPIO register or local
bus space.
2) Read the address of writing.
Allow at least 8 bus-clock cycles for
cancellation and the INTC response
time.
1) Set the corresponding bit in
INTMSK0/1 to 1.
2) Set the corresponding bit in
INTMSKCLR0/1 to 1.
3) Read INTMSK0/1.
Start of IRQ level-sense or IRL
level-encoded interrupt (IRQ/IRL
level interrupt) handling
Figure 10.5 Example of Interrupt Handling Routine
To cancel an interrupt request after its acceptance by the CPU, the external device that generated
the request must be notified of its acceptance. The method of notification might take the form of
using the GPIO to output the acceptance level or interrupt pin information, or writing to a special
address in the local bus space. It is necessary to consecutively execute writing to and reading from
the GPIO register or the special location in the local bus space.
After clearing an interrupt request that is held in the detection circuit, ensure that the time required
for the CPU to detect the interrupt has elapsed. To ensure this time, consecutively execute writing
to INTMSK0/1 and INTMSKCLR0/1 and reading of INTMSK0/1.
Summary of Contents for SH7780 Series
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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 ...
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