CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Telephone Function)

R10HIZ–R13HIZ: R1 port high impedance control register (FF32H)

Controls high impedance output of the output port.

When "1" is written: High impedance

When "0" is written: Data output

Reading: Valid

When using the XTMUTE, XRMUTE, HDO and HFO outputs, fix these registers at "0". R10HIZ, R11HIZ, R12HIZ and R13HIZ correspond to the XTMUTE, XRMUTE, HDO and HFO outputs, respectively.

At initial reset, these registers are set to "0".

R10–R13: R1 output port data register (FF33H)

Set the output data for the output ports.

When "1" is written: High level output

When "0" is written: Low level output

Reading: Valid

When using the XTMUTE, XRMUTE, HDO and HFO outputs, fix these registers at "1". R10, R11, R12 and R13 correspond to the XTMUTE, XRMUTE, HDO and HFO outputs, respectively.

At initial reset, these registers are all set to "1".

CTMO: R10 output selection register (FF13H•D0)

Selects the R10 terminal function.

When "1" is written: XTMUTE output

When "0" is written: General-purpose DC output

Reading: Valid

When using the R10 terminal for the XTMUTE output, write "1" to this register. Furthermore, fix the R10 register at "1" and the R10HIZ register at "0".

The XTMUTE output is controlled by the CTMUT register (FF18H•D0). At initial reset, this register is set to "0".

CRMO: R11 output selection register (FF13H•D1)

Selects the R11 terminal function.

When "1" is written: XRMUTE output

When "0" is written: General-purpose DC output

Reading: Valid

When using the R11 terminal for the XRMUTE output, write "1" to this register. Furthermore, fix the R11 register at "1" and the R11HIZ register at "0".

The XRMUTE output is controlled by the CRMUT register (FF18H•D1). At initial reset, this register is set to "0".

CHDO: R12 output selection register (FF13H•D2)

Selects the R12 terminal function.

When "1" is written: HDO output

When "0" is written: General-purpose DC output

Reading: Valid

When using the R12 terminal for the HDO output, write "1" to this register. Furthermore, fix the R12 register at "1" and the R12HIZ register at "0".

The HDO output is controlled by the HOLD register (FF14H•D2). At initial reset, this register is set to "0".

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S1C63558 TECHNICAL MANUAL