Interrupt - Epson S1C63558 Technical Manual

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Telephone Function)

4.14.9 Interrupt

The dialer has three types of interrupt generation functions.
(1) Dialing interrupt
Tone mode
In the tone mode, 94 msec of an inter-digit pause is made after a tone signal (mim. 94 msec, can be
prolonged by the CTO register) is output completely. A dialing interrupt occurs immediately follow-
ing the inter-digit pause. See the timing chart in Figure 4.14.4.2.
Pulse mode
In the pulse mode, the inter-digit pause set by the IDP register is made after a dial pulse digit is
output completely. A dialing interrupt occurs immediately following the inter-digit pause. See the
timing chart in Figure 4.14.5.2.
(2) Pause interrupt
When the pause function is executed, an interrupt occurs when the pause time (1 to 15 sec) set by the
PTS register has passed after writing "1" to the PAUSE bit. See the timing chart in Figure 4.14.6.1.
(3) Flash interrupt
When the flash function is executed, 938 msec of a flash pause is made when the flash time (94 to
1,406 msec) set by the FTS register has passed after writing "1" to the FLASH bit. A flash interrupt
occurs immediately following the flash pause. See the timing chart in Figure 4.14.7.1.
The interrupt factor flag ID (FFF9H•D0) is set to "1" when an interrupt occurs. The interrupt request will
be delivered to the CPU only when the interrupt mask register EID (FFE9H•D0) is set to "1".
If the EID register is set to "0", the interrupt request will be masked. However, the ID flag will be set at the
above |Iming regardless of the EID register setting. So operation status can also be checked by reading the
ID flag.
The ID flag is reset by writing "1". It must be reset for the next interrupt after an interrupt has occurred.
126
EPSON
S1C63558 TECHNICAL MANUAL