Oki JOB60851 user manual Read and write Functions, read Operation

Chapter 4 Software Development

Receive end interrupt flag	"0"
(3) Configuring TX and RX pins

These pins represent secondary functions for Port 7 pins 1 and 0, respectively, so write the following values to the corresponding bits in the Port Mode (P7IO) and Port Secondary Function Control (P7SF) Registers.

Port Mode (P7IO):	"1"	(output) for P7_1 and "0" (input) for P7_0
Port Secondary Function Control (P7SF):	"1"	(secondary) for both P7_1 and P7_0

This completes the serial port setup procedure.

4-5-3. read() and write() Functions

For full particulars on these two functions, refer to the comments in the source code file stdrw573.c. This section gives just broad outlines.

(1)read() function

Figure 4.5.3 gives a flowchart for function operation.

Read character from receive buffer
Character is carriage	Character is not carriage
return	return
Echo character (carriage	Echo character to
return) to terminal	terminal
Echo line feed to
terminal
Save newline (line feed)	Save character in
in memory	memory

Figure 4.5.3. read() Operation

The function reads the character in the single-byte receive buffer.

If that character is not a carriage return, the function echoes it back to the terminal emulator and stores it as is in memory (as specified by the user application program), incrementing a buffer

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