Texas Instruments MSC1211 manual I/O Connectors and Signals, 1 J8 Serial0 RS-232 Connector

I/O Connectors and Signals

3.3 I/O Connectors and Signals

The various connectors on the MSC1211EVM are described in this section.

3.3.1J8: Serial0 RS-232 Connector

The host PC communicates with the MSC1211EVM through this connector, which is a D-shell type, 9-pin female, pinned out in the usual manner. Some of the flow control lines are used for special purposes by the MSC1211EVM board; these are described in Table 3–4.

In the RS-232 electrical specification, –5V to –15V on a line indicates a logic high (mark), and +5V to +15V indicates logic low (space). Line states are de- scribed here according to their logical states.

If a non-handshaking RS-232 cable is used (i.e., one that connects only RD, TD, and signal ground), the board can still operate normally, but it cannot be reset by the host PC, and bootstrap firmware upgrading cannot be performed through the serial port.

Table 3–4. J8: RS-232 Port Pinout

Pin	Signal	RS-232	Direction
Number	Name	Name	(at board)	Function
1	DCD	Data Carrier Detect	Output	None
2	RD	Receive Data	Output	Serial data output to the host PC
3	TD	Transmit Data	Input	Serial data input from the host PC
4	DTR	Data Terminal Ready	Input	Connected to the reset circuit.
				A low-to-high transition on this line
				resets the MCU.
5	SG	Signal Ground	Power	Ground reference
6	DSR	Data Set Ready	Output	None
7	RTS	Request To Send	Input	Connected to PROG LOAD
				function. Used to enter serial
				programming mode.
				A high-to-low transition resets the
				MCU and puts it into serial
				programming mode.
8	CTS	Clear To Send	Output	None
9	RI	Ring Indicator	Output	None

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