Epson S1C63558 manual 131

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Telephone Function)

HSON		"0"
(FF18H•D3)
Data bus		2		3			3
Wite to TCD
		"0"
(FF17H)			Make
	DP	"0"
			Break		tIDP	tIDP		tIDP
XRMUTE(R11)					tMH			tMH
		"1"

XTMUTE(R10) "1"

Interrupt request

tIDP: Inter-digit pause time

tMH: Mute hold time

Fig. 4.14.5.2 Pulse output timing chart

When data is written to the TCD register, the specified number of pulses are output from the DP terminal. At the same time, XRMUTE (R11) and XTMUTE (R10) terminals go Low level.

When the pulses have been output completely, the DP terminal returns to High level, then the specified inter-digit pause will be inserted.

An interrupt occurs when the inter-digit pause time has passed. It allows transmission of the next dial pulses.

The XRMUTE (R11) and XTMUTE (R10) terminals keep on Low level for 4 msec of mute hold time (tMH) after the inter-digit pause is released. If the next pulse output does not start in this period, the XRMUTE (R11) and XTMUTE (R10) terminals return to High level. When the next pulse output starts in the mute hold period, the XRMUTE (R11) and XTMUTE (R10) terminals will stay in Low level.

Note that the CTMUT register (FF18H•D0) and CRMUT register (FF18H•D1) must be set to "1" when the above mute function (XTMUTE and XRMUTE control) is used.

The following summarizes a dialing procedure in the pulse mode:

1.Write "1" to the HSON register.

2.Write a dial number to the TCD register. (pulse output starts)

3.Reset the interrupt factor flag after an interrupt has occurred.

4.Repeat steps 2 to 3 for the number of dial digits.

:

Communication

:

5. Write "0" to the HSON register after communication is finished.

S1C63558 TECHNICAL MANUAL EPSON 121