Specifications

Chapter 3 Hardware
ReadyBoard 800 Reference Manual 37
Serial A Interface (J15A/B)
Table 3-8. Serial A (Serial 1) Interface Pin/Signal Descriptions (J15A)
Pin
#
Signal Description
1 DCD1* Data Carrier Detect 1 – Indicates external serial communications device is detecting
a carrier signal (i.e., a communication channel is currently open). In direct connect
environments, this input is driven by DTR1 as part of the DTR/DSR handshake.
2 RXD1 Receive Data 1 – Serial port 1 receive data in
3 TXD1 Transmit Data 1 – Serial port 1 transmit data out
4 DTR1*
Data Terminal Ready 1 – Indicates Serial port 1 is powered, initialized, and ready.
Used as hardware handshake with DSR1 for overall readiness to communicate.
5 GND Ground
6 DSR1*
Data Set Ready 1 – Indicates external serial communications device is powered,
initialized, and ready. Used as hardware handshake with DTR1 for overall readiness
to communicate.
7 RTS1*
Request To Send 1 – Indicates Serial port 1 is ready to transmit data. Used as
hardware handshake with CTS1 for low level flow control.
8 CTS1* Clear To Send 1 – Indicates external serial communications device is ready to
receive data. Used as hardware handshake with RTS1 for low level flow control.
9 RI1* Ring Indicator 1 – Indicates external serial communications device is detecting a
ring condition. Used by software to initiate operations to answer and open the
communications channel.
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.
Table 3-9. Serial A (Serial 2) Interface Pin/Signal Descriptions (J15B)
Pin # Signal Description
1 DCD2* Data Carrier Detect 2 – Indicates external serial communications device is detecting
a carrier signal (i.e., a communication channel is currently open). In direct connect
environments, this input is driven by DTR2 as part of the DTR/DSR handshake.
2 RXD2 Receive Data 2 – Serial port 2 receive data in
3 TXD2 Transmit Data 2 – Serial port 2 transmit data out
4 DTR2*
Data Terminal Ready 2 – Indicates Serial port 2 is powered, initialized, and ready.
Used as hardware handshake with DSR2 for overall readiness to communicate.
5 GND Ground
6 DSR2*
Data Set Ready 2 – Indicates external serial device is powered, initialized, and
ready. Used as hardware handshake with DTR2 for overall readiness.
7 RTS2* Request To Send 2 – Indicates Serial port 2 is ready to transmit data. Used as
hardware handshake with CTS2 for low level flow control.
8 CTS2* Clear To Send 2 – Indicates external serial communications device is ready to
receive data. Used as hardware handshake with RTS2 for low level flow control.
9 RI2*
Ring Indicator 2 – Indicates external serial device is detecting a ring condition.
Software initiates operation to answer and open the communications channel.
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.