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CARD-PCI/GX Hardware Manual
EPSON
Rev.A
32
3.3.7 Serial interfaces
SCE8720C supports 2 ports of serial interfaces by 16550-compatible UART.
Signal name
(16 pins in total)
I/O
Function description
COM1CD#
COM2CD#
I
Data carrier detect
Active low
Signal which indicates that the modem or data terminal has
detected the carrier.
COM1DTR#
COM2DTR#
O
Data terminal ready
Active low
Signal which indicates that SCE8720 is ready for data
transmission with respect to the modem or data terminal.
COM1DSR#
COM2DSR#
I
Data set ready
Active low
Signal which indicates that the modem or data terminal is
ready for data transmission with respect to SCE8720C..
COM1RTS#
COM2RTS#
O
Request to send
Active low
Signal which indicates that SCE8720 has transmission data
ready, and indicates a request to transmit data with respect
to the modem or data terminal.
COM1CTS#
COM2CTS#
I
Clear to send
Active low
Signal which indicates that the modem or data terminal has
become ready to receive for the SCE8720C’s request to send.
COM1RI#
COM2RI#
I
Ring indicator
Active low
Signal which indicates that the modem or data terminal has
detected a telephone ringing signal.
Alternatively, this signal can be used in SCE8720C as a
wake-up signal from the suspend state.
COM1TXD
COM2TXD
O
Serial data transmission
Output pin for the asynchronous serial data.
COM1RXD
COM2RXD
I
Serial data receive
Input pin for the asynchronous serial data.