z8f1621 ZiLOG Semiconductor, z8f1621 Datasheet - Page 136

• Manufacturer Part Number: z8f1621
• Description: High Performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS019921-0308
Baud Rate
IR_TXD
UART’s
Clock
TXD
Transmitting IrDA Data
Receiving IrDA Data
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:
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-clock 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, a 3-clock high pulse is output
following a 7-clock low period. After the 3-clock high pulse, a 6-clock low pulse is output
to complete the full 16-clock data period.
When the Infrared Endec is enabled, the UART’s TXD signal is internal to the Z8 Encore!
XP
Data received from the infrared transceiver via the IR_RXD signal through the
decoded by the Infrared Endec and passed to the UART. The UART’s baud rate clock is
used by the Infrared Endec to generate the demodulated signal (RXD) that drives the
UART. Each UART/Infrared data bit is 16-clocks wide.
7-clock
delay
®
Start Bit = 0
16-clock
F64XX Series products while the IR_TXD signal is output through the TXD pin.
Infrared Data Rate (bits/s)
period
3-clock
pulse
Figure 19. Infrared Data Transmission
Data Bit 0 = 1
=
----------------------------------------------------------------------------------------- -
16
Data Bit 1 = 0
×
System Clock Frequency (Hz)
UART Baud Rate Divisor Value
Figure 19
Data Bit 2 = 1
displays IrDA data transmission.
Z8 Encore! XP
Figure 20
Product Specification
displays data reception.
Infrared Encoder/Decoder
Data Bit 3 = 1
®
F64XX Series
RXD
pin is
122