6 inTeRRuPT COnTROlleR
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
6-1
(Rev. 1.1)
Interrupt Controller
6
Configuration of interrupt Controller
6.1
The S1C63003/004/008/016 supports the interrupts listed below.
1.1 Interrupt types
Table 6.
Interrupt
S1C63016
S1C63008
S1C63004
S1C63003
External interrupt
Key input interrupt
8 systems
4 systems
Internal interrupt
Watchdog timer interrupt
NMI, 1 system
Programmable timer interrupt
8 systems
6 systems
1 system
Serial interface interrupt
1 system
–
Clock timer interrupt
8 systems
4 systems
Stopwatch timer interrupt
4 systems
2 systems
R/F converter interrupt
3 systems
To enable an interrupt, the interrupt flag must be set to "1" (EI) and the corresponding interrupt mask register must
be set to "1" (enable).
When an interrupt occurs, the interrupt flag is automatically reset to "0" (DI), and interrupts after that are disabled.
The watchdog timer interrupt is an NMI (non-maskable interrupt), therefore, the interrupt is generated regardless of
the interrupt flag setting. Also the interrupt mask register is not provided. However, it is possible to disable NMI since
software can stop the watchdog timer operation.
Figure 6.1.1 shows the configuration of the interrupt circuit.
Note: After an initial reset, all the interrupts including NMI are masked until both the stack pointers SP1
and SP2 are set with the software. Be sure to set the SP1 and SP2 in the initialize routine.
Further, when re-setting the stack pointer, the SP1 and SP2 must be set as a pair. When one of
them is set, all the interrupts including NMI are masked and interrupts cannot be accepted until the
other one is set.