abstract.txt

针对飞利浦LPC214x的虚拟串口程序

The Virtual COM port project is a demo program for the Keil MCB2140
Board using the Philips LPC214x Microcontroller.

It demonstrates an USB Virtual COM port based on a customized 
USB host driver.

Once the Virtual COM port device driver is installed on the LPC214x.
Unplug then replug-in the USB cable, the PC will detect the USB
device and look for corresponding USB host driver.

The host driver came with the sample software is under
"PLPU-S2K" directory. The PC will install two virtual COM ports 
one after another on the PC. Once the installation is done, on the PC
System/Hardware/Device Manager/Ports(COM&LPT), they will be two
more virtual COM ports appeared as "Philips USB to Serial Adaptor(COMx)".  
Number "x" is not fixed as different PC configuration may have different 
"x" displayed on the device manager. The USB host driver assigns "x" 
dynamically based on the existing COM port configuration of the system.
   
There are two ways to test the USB Virtual COM ports:

  (1) With serial cable: open two Hyperterminal windows,
One uses the "Philips USB to Serial Adaptor(COMx)", the smaller
number "COMx" will communicate with COM0 on MCB214x, the larger number
"COM(x+1)" will communicate with COM1 on MCB214x. If you connect PC COM 
port COM0 to MCB214x COM0, open "COM0" and "COMx". If you connect PC
COM port COM0 to MCB214x COM1, open "COM0" and "COM(x+1)"
  Please note, if use COM0 of MCB214x, be sure to remove two jumbers, 
"RST" and "ISP" on MCB214x.
  Type in data from COM0 will echo on "COMx" and type in data
from COM1 will echo on "COM(x+1)", visa versa. So, this is bi-directional
communication between the physical COM port 0 and 1 on MCB214x and 
the virtual COM ports, COMx and COM(x+1) on host PC.    

  (2) Without serial cable: go to vcomuser.h, change line 
"#define NO_UART_CABLE 0" to "#define NO_UART_CABLE 1", recompile 
the project and update the flash.
   Once the flash has been updated. Unplug and replug-in the USB cable 
to reset the MCB214x board.
   Open one or both virtual COM ports as mentioned earlier, "COMx"
and/or "COM(x+1)", type in any data from hyper-terminal windows, the 
ASCII data will be shown on the LEDs on MCB214x board, e.g. type in "1"
on the hyper terminal will result in "00110001B" on LEDs from P1.16 to P1.23.
If the INT1 button is pressed, the message "INT1 has been pressed" 
will be shown on "COMx" and "COM(x+1)" simultaneously. This indicates
that the MCB214x has communicated with the host PC hyper terminals via 
USB virtual COM ports in both directions.

The Virtual COM Port program is available for the following targets:
  MCB2140 Board: configured for on-chip Flash ROM
                 (used for production or target debugging)