4

Appendix F: General Application Guide for the ASDL-3023

Remote Control Drive Modes

The ASDL-3023 can operate in the single-TxD program-

mablemodeorthetwo-TxDdirecttransmissionmode.

Single-TxD Programmable Mode

In the single-TxD programmable mode, only one input

pin (TxD_IR input pin) is used to drive the LED in both

IrDAmodeaswellasRemoteControlmodeofoperation.

Thismodecanbeusedwhentheexternalcontrolleruses

onlyonetransmitpinforbothIrDAaswellRCmodeof

operation.

transceiver is in default mode (IrDA-SIR) when powered

up.Theuserneedstoapplythefollowingprogramming

sequencetoboththeTxD_IRandSDinputstoenablethe

transceivertooperateineithertheIrDAorremotecontrol

mode.

Mode Programming Timing Table

Thefollowingtimingsdescribeinputconstraintsrequiredusingtheactiveserialinterfaceformodeprogrammingwith

pinsSD,TxIR,andTxRC:

Parameter

Symbol

Min

Typ

Max

Unit

Notes

Shutdowninputpulsewidth,atpinSD

30

-

∞

µs

Willactivate

completeshutdown

SDmodesetuptime

200

-

-

Ns

Setupformode

programming

TxIRpulsewidthforRCmode

200

-

-

Ns

RCdriveenabled

withpinTxIR

SDprogrammingpulsewidth

Note:(tA+tB)<tC<tSDPW

-

-

5.0

µs

Pulsewidthmode

programming

TxIRsetuptimefor

SIRorMIR/FIRmode

50

-

-

Ns

SetuptimeforIrDA

bandwidthselection

TxIRorSDholdtimetolatch

SIR,MIR/FIRorRCmode

50

-

-

Ns

HoldtimeforIrDAorRC

modes

Two-TxD Direct Transmission Mode

In the two-TxD direct transmission mode, the LED can

bedrivenseparatelyforIrDAandRCmodeofoperation

through the TxD_IR and TxD_RC pins respectively. This

mode can be used when the external controller utilizes

separatetransmitpinsforIrDAandRCoperationmodes,

therebyeliminatingtheneedforexternalmultiplexing.

Please refer to the Transceiver I/O truth table for more

detail.

Transceiver Control I/O Truth Table for Two-TxD Direct

TransmissionMode

SD

TxIR

TxRC

LED

Remarks

0

0

0

OFF

IRRxenabled.Idlemode

0

0

1

ON

Remotecontroloperation

0

1

0

ON

IrDATxoperation

0

1

1

-

Notrecommended

(BothTransmittersoff)

1

0

0

OFF

Shutdownmode*

* Theshutdownconditionwillsetthetransceivertothedefaultmode

(IrDA-SIR)

tC

tB

tA

tTL

tC

SHUTDOWN

DRIVE

IrDA LED

DRIVE

RC LED

RC

MODE

RESET

DRIVE

IrDA LED

SHUTDOWN

(ACTIVE HIGH)

TxIR

(ACTIVE HIGH)

TxRC

(GND)

tH

tH

tH