Advantech SOM 144, Design Specification

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Chapter 3 Signal Description 11
device to terminate current transaction. After re-
ceiving this input, IDE device will de-assert DRQ
to STOP current transaction.
PIDE_IRQ Interrupt signal.
HDRST# Low active hardware reset (RSTDRV inverted).
3.1.3 Serial Ports
All signals are TTL level signals. External drivers are necessary to
convert the TTL signals to the desired physical interfaces, such as
RS232, RS422,or RS485.
DCD1#, DCD2# This active low input for serial port. Handshake
signal which notifies the UART that carrier signal
is detected by the modem.
DSR1#, DSR2# This active low input is for serial port. Handshake
signal which notifies the UART that the modem is
ready to establish the communication link.
RXD1, RXD2 Receiver serial data input.
RTS1#, RTS2# This active low output for serial port. Handshake
signal notifies the modem that the UART is ready
to transmit data.
TXD1, TXD2 Transmitter serial data output from Serial port.
CTS1#, CTS2# This active low input for serial ports . Handshake
signal which notifies the UART that the modem is
ready to receive data.
DTR1#, DTR2# Active low data terminal ready outputs for the seri-
al port. Handshake output signal notifies modem
that the UART is ready to establish data communi-
cation link.
RI1#, RI2# This active low input is for the serial port. Hand-
shake signal which notifies the UART that the tele-
phone ring signal is detected by the modem.
3.1.4 USB
All pullups are integrated on the SOM 144 Module. For ESD and