W83787IF Datasheet, PDF (44/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
4.2.9 User-defined Register (UDR) (Read/Write)
This is a temporary register that can be accessed and defined by the user.
4.2.10 IRQ3/IRQ4 Setting
IRQ3 and IRQ4 are the interrupt pins for UARTA and UARTB in the W83787IF. These two interrupt
pins switch automatically inside the chip depending on the address setting of UARTA and UARTB.
When the address of UARTA or UARTB is selected as COM1 or COM3, interrupt requests for the
UART are sent out of W83787IF via IRQ4. If the address of UARTA or UARTB is selected as COM2
or COM4, interrupts are sent out via IRQ3. Thus when UARTA is set as COM1, UARTB should not be
set as COM3, and vice versa. When UARTA is set as COM2, UARTB should not be set as COM4,
and vice versa.
4.3 Infrared Interface
The infrared interface supports a two-way wireless communication using infrared as a
transceiver/receive media. It uses a UART B port to serve as data transmission and supports IrDA
and Amplitude Shift Keyed IR (ASK-IR).
In the IrDA mode, the serial transmission maximum baud rate can be up to 115.2k. When the UART
B send a zero signal, the IRTX encoder encodes a pulse width with 3/16 bit-time or fixed 1.6us to
output on IR emitter. If UART B send a high signal, then the encoder have no data output to IR
emitter. The decoder receiving a pulse with 3/16 bit-time or 1.6us represents a start bit. (Refer to AC
timing for the parameters of the IrDA waveform).
In the ASK-IR mode, the serial transmission maximum baud rate is only 19200 bps. When the UART
B send a zero signal, the encoder modulate 500KHZ sending to IR emitter. (Refer to AC timing for the
parameters of the ASK-IR waveform).
In the half duplex, the receiver does not receive any input data when transceiver transmit data. That
is, during the transmission, the receiver does not disturb it-self from the self-emitter.
5.0 PARALLEL PORT
5.1 Printer Interface Logic
The parallel port of the W83787IF makes possible the attachment of various devices that accept eight
bits of parallel data at standard TTL level. The W83787IF supports an IBM XT/AT compatible parallel
port (SPP), bi-directional parallel port (BPP), Enhanced Parallel Port (EPP), Extended Capabilities
Parallel Port (ECP), Extension FDD mode (EXTFDD), Extension 2FDD mode (EXT2FDD), Extension
Adapter mode (EXTADP), and JOYSTICK mode on the parallel port. Refer to the configuration
registers for more information on disabling, power-down, and changing the base address of the
parallel port and on selecting the mode of operation.
Table 5-1 shows the pin definitions for different modes of the parallel port.
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Publication ReleaseDate:Sep 1995
Revision A1