Compaq COM-2(PC)F Computer Hardware User Manual


 
Appendix
COM-2(PC)F 55
Sample Program 11
[Data transmission and reception (COM3, COM4 mode)]
Sample program 11 uses the bios_serialcom( ) function for MS-C.
It first receives the data transmitted from COM3, and then receives
the data at COM3 transmitted from COM4. Received data is
displayed on the CRT.
1
COM3
Initialization
1
COM4
Initialization
Transmit 1-byte
Data from COM3
START
END
No
Yes
No
COM4 status check
ready to receive?
Yes
COM3
Initialization
COM4
Initialization
Transmit 1-byte
Data from COM4
No
Yes
COM3
Data Reception
No
Yes
COM4
Data Reception
Data reception A to K
from COM3 completed?
COM3 status check
ready to receive?
Data reception a to k
from COM4 completed?
Figure 6.13. Flowchart of Sample Program 11