User`s manual

User’s Manual 21
3.1.3 Serial Communication
The following sample programs can be found in the
SAMPLES\RCM2000 folder.
Two sample programs, CORE_FLOW-
CONTROL.C
and CORE_PARITY.C,
are available to illustrate RS-232
communication. To run these sample
programs, you will have to add an
RS-232 transceiver such as the
MAX232 at location U2 and four
100 nF charge-storage capacitors at
C3–C6 on the Prototyping Board.
Also install the 2 × 5 IDC header
included with the Prototyping Board
accessory parts at J6 to interface the
RS-232 signals.
The diagram shows the connections.
• CORE_FLOWCONTROL.C—This
program demonstrates hardware flow control by configuring Serial Port C (PC3/PC2)
for CTS/RTS with serial data coming from TxB at 115,200 bps. One character at a time
is received and is displayed in the STDIO window.
To set up the Prototyping Board, you will need to tie PC4 and PC5
(TxB and RxB) together at header J4, and you will also tie PC2 and
PC3 (TxC and RxC) together as shown in the diagram.
A repeating triangular pattern should print out in the STDIO window.
The program will periodically switch flow control on or off to demon-
strate the effect of no flow control.
Refer to the serBflowcontrolOn() function call in the Dynamic C Function Refer-
ence Manual for a general description on how to set up flow control lines.
• CORE_PARITY.C—This program demonstrates the use of parity modes by repeatedly
sending byte values 0–127 from Serial Port B to Serial Port C. The program will switch
between generating parity or not on Serial Port B. Serial Port C will always be checking
parity, so parity errors should occur during every other sequence.
To set up the Prototyping Board, you will need to tie PC4 and PC3
(TxB and RxC) together at header J4 as shown in the diagram.
The Dynamic C STDIO window will display the error sequence.
+
C1
U1
J5
S2
S3
S1
RN1
D2
JP1
DS3
DS2
DS1
C2
U2
C3
C4 C5
J6
C6
RESET
S2
PB3
PB2
PA1
PA0
DS3
S3
DS2
PWR
GND
RXB
TXB
TXCRXC
RS-232
MAX232
100 nF
storage
capacitors
J6
RxC TxC
GND
TxB RxB
J6
RxC TxC
GND
TxB RxB