Zilog eZ80F92 - Manual (Page 55)

eZ80F92 Development Kit
User Manual
UM013911-0607 Operational Description
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however, it cannot do both at the same time. Only a few registers are
required to configure the UART0 port to send and receive IrDA data.
The RxD and TxD signals on the transceiver perform the same functions
as a standard RS232 port. However, these signals are processed as IrDA
3/16 coding pulses (sometimes called IrDA encoder/decoder pulses).
When the IrDA function is enabled, the final output to the RxD and TxD
pins are routed through the 3/16 pulse generator.
Another signal that is used in the eZ80F92 Flash Module’s IrDA system is
Shut_Down (SD). The SD pin is connected to PD2 on the eZ80F92 Flash
Module. The IrDA control software on the user’s wireless device must
enable this pin to wake the IrDA transceiver. The SD pin must be set Low
to enable the IrDA transceiver. On the eZ80F92 Flash Module, a two-
input OR gate is used to allow an external pin to shut down the IrDA
transceiver. Both pins must be set Low to enable this function.
Figure 14 highlights the eZ80F92 Flash Module IrDA hardware connec-
tions.
The eZ80F92 Flash Module features an Infrared Encoder/Decoder regis-
ter that configures the IrDA function. This register is located at address
0BFh
in the internal I/O register map.
The Infrared Encoder/Decoder register contains three control bits. Bit 0
enables or disables the IrDA encoder/decoder block. Bit 1, if it is set,
Figure 14. IrDA Hardware Connections
External Disable
eZ80L92
Device
IrDA
PD2(IR_SD)
PD1(RxD)
PD0(TxD)
SD
RD
TD