S1C63567 TECHNICAL MANUAL
EPSON
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CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Telephone Function)
CRMUT: Receive mute control (FF18HD1)
Controls the receive mute.
When "1" is written: Receive mute output
When "0" is written: Low level output on XRMUTE (R11) terminal
Reading: Valid
When "0" is written to the CRMUTE register, the XRMUTE (R11) terminal is pulled down to Low (VSS)
level to mute the receive line.
When the CRMUTE register is set to "1", the XRMUTE (R11) terminal is controlled by the hardware and
will be Low (VSS) level during a dialing pulse cycle or a flash cycle.
At initial reset, this register is set to "1".
CTMUT: Transmit mute control (FF18HD0)
Controls the transmit mute.
When "1" is written: Transmit mute output
When "0" is written: Low level output on XTMUTE (R10) terminal
Reading: Valid
When "0" is written to the CTMUTE register, the XTMUTE (R10) terminal is pulled down to Low (VSS)
level to mute the transmit line.
When the CTMUTE register is set to "1", the XTMUTE (R10) terminal is controlled by the hardware and
will be Low (VSS) level during a dialing pulse cycle, flash cycle, dialing tone cycle or a hold-line cycle.
At initial reset, this register is set to "1".
HSON: Hook switch ON/OFF (FF18HD0)
Controls the hook switch.
When "1" is written: Hook OFF
When "0" is written: Hook ON
Reading: Valid
When the HSON register is set to "1", the DP terminal goes High (VDD) level and the hook switch goes to
off-hook status.
At initial reset, this register is set to "0".
CTO: Continuous output tone selection (FF16HD3)
Selects the tone duration time to continuous output or not.
When "1" is written: Continuous
When "0" is written: 94 msec
Reading: Valid
This register is used to decide the tone duration time. The minimum value of tone duration time is 94
msec.
When the CTO register is set to "1", a tone signal will be output until the CTO register is changed to "0". If
the period (CTO is changed from "1" to "0"), that is controlled by the CTO register, is less than the mini-
mum tone duration time (94 or 47 msec), the duration time will be prolonged to the minimum tone
duration time.
When the CTO register is set to "0", a tone signal will be output with the minimum tone duration time.
This setting is valid only for tone mode.
At initial reset, this register is set to "0".