Z8F1680SH020SG Datasheet, PDF (208/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
183
endec and passed to the UART. Communication is half-duplex, that is, simultaneous data
transmission and reception is not allowed.
The baud rate is set by the UART’s Baud Rate Generator and supports IrDA standard baud
rates from 9600 baud to 115.2 KBaud. Higher baud rates are possible, but do not meet
IrDA specifications. The UART must be enabled to use the infrared endec. The infrared
endec data rate is calculated using the following equation:
Infrared Data Ratebits  s
=
---------^S----^y---^s----^t--^e----^m------^C-----^l-^o----^c---^k-----^F----^r---^e----^q---^u----^e----ⁿ---^c----^y---^--^H-----^z----^--------
16  UART Baud Rate Divisor Value
13.2.1. Transmitting IrDA Data
The data to be transmitted using the infrared transceiver is first sent to the UART. The
UART’s transmit signal (TXD) and baud rate clock are used by the IrDA to generate the
modulation signal (IR_TXD) that drives the infrared transceiver. Each UART/infrared
data bit is 16 clocks wide. If the data to be transmitted is 1, the IR_TXD signal remains
Low for the full 16-clock period. If the data to be transmitted is 0, the transmitter first
outputs a 7-clock Low period, followed by a 3-clock High pulse. Finally, a 6-clock Low
pulse is the output to complete the full 16 clock data period. Figure 28 displays IrDA data
transmission. When the infrared endec is enabled, the UART’s TXD signal is internal to
the Z8 Encore! XP F1680 Series products while the IR_TXD signal is the output through
the TXD pin.
16-clock
period
Baud Rate
Clock
UART’s
TXD
IR_TXD
Start Bit = 0
3-clock
pulse
Data Bit 0 = 1
Data Bit 1 = 0
Data Bit 2 = 1
Data Bit 3 = 1
7-clock
delay
Figure 28. Infrared Data Transmission
PS025015-1212
PRELIMINARY
Infrared Encoder/Decoder