UPSD3422_06 Datasheet, PDF (112/293 Pages) STMicroelectronics – Turbo Plus Series Fast Turbo 8032 MCU with USB and Programmable Logic

IrDA interface
uPSD34xx
The UART1 serial channel can operate in one of four different modes as shown in Table 46
on page 100 in Section 21: Serial UART interfaces on page 99. However, when UART1 is
used for IrDA communication, UART1 must operate in Mode 1 only, to be compatible with
IrDA protocol up to 115.2k bps. The IrDA interface will support baud rates generated from
Timer 1 or Timer 2, just like standard UART serial communication, but with one restriction.
The transmit baud rate and receive baud rate must be the same (cannot be different rates as
is allowed by standard UART communications).
The IrDA Interface is disabled after a reset and is enabled by setting the IRDAEN Bit in the
SFR named IRDACON (Table 50 on page 112). When IrDA is disabled, the UART1's RxD
and TxD signals will bypass the internal IrDA logic and instead they are routed directly to the
pins RxD1 and TxD1 respectively. When IrDA is enabled, the IrDA pulse shaping logic is
active and resides between UART1 and the pins RxD1 and TxD1 as shown in Figure 39 on
page 111.
22.1
Baud rate selection
The IrDA standard only supports 2.4, 9.6, 19.2, and 115.2kbps. Table 52 on page 113
informs the IrDA Interface of the baud rate of UART#1 so that it can perform pulse
modulation properly. It may not be necessary to implement the BR[3:0] bits in the IRDACON
Register if the IrDA Interface obtains the proper timing from UART#1.
Table 50.
Bit 7
–
IRDACON register bit definition (SFR CEh, reset value 0Fh)
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
IRDAEN PULSE CDIV4
CDIV3
CDIV2
CDIV1
Bit 0
CDIV0
Bit
Symbol
R/W
7
–
–
Reserved
IrDA Enable
Definition
6
IRDAEN
RW _{0 = IrDA Interface is disabled}
1 = IrDA is enabled, UART1 outputs are disconnected from
Port 1 (or Port 4)
IrDA Pulse Modulation Select
5
PULSE
RW
0 = 1.627µs
1 = 3/16 bit time pulses
4-0
CDIV[4:0]
RW Specify Clock Divider (see Table 53 on page 114)
112/293