xl2000 Frequently Asked Questions 

If you are a beginner, then I strongly recommend that you carefully read the following. When you have something wrong in the experiment, you can get back here anytime to have a review.

1 Why my XL2000 programming package is always displaying:  the selected serial port does no exist, please choose another one?

   a. Check if power is on, and power indicator light is on.
   b. Check if programming/simulation switch button is set at the correct state. The button state must be on when do programming.

   c. Check if any other software occupies serial port, such as other programmer, debugger or keil uv2 simulation software. The same serial port can only support one program at the same time, else confliction exists.

   d. Check if serial port selection is OK. You can open Control Panel/System/Hardware property /serial ports and see the port number. Make sure the selection is consistent with the allocation number.
   e. Check if the USB drive is installed correctly. (Refer to Chapter III: USB Installation Guide)
   f. Check if USB/RS232 jumper is OK, if you use USB, then JP13/JP14 must set to USB.

2. Why XL2000 does not act after prompted with success programming and target board is running?

   a. Check if the chip on the board socket is 89S51. Other chip does not work.

   b. Check if the serial port is connected correctly with pin lines. The result can only be displayed on some experimental resources such as LCD/LED. This output resources should be connected to CPU output port by pin lines correctly.
   c. Check if the system is reset well. You can have a try to press down the RESET button.

3. In simulation mode, why the board cannot connect to my PC?

   a. Check if the simulation module in the package is locked well on the socket. 

   b. Check if keil uv2 software version is OK. Strongly suggest using the keil uv2 software in the package shipped to you. ( Some other versions keil is not compatible.) Attention: the keil software must be installed under the root of c disk, which means c:\. Other directory does not work. (Refer to Chapter V, XL2000 simulating operation guide). The file must be named ascii and placed under ascii folder.

   c. Check if the COM port configuration is OK. Because simulation and programming are both using COM ports, when doing simulation, other software that is using COM port must be closed.

   d. Check if programming /simulation button state is OK. ( down button means simulation)

4. Why the simulation head works well with on board resources but does not work with external board?

   a. Check if the external board is reset well, the oscillator is OK and the programming functionality is OK of the board?

   b. Check if the simulation head is plugged correctly. The first PIN(red) must be connected to the first PIN of the CPU. You can verify it with a multi-meter.

5. Why some program works under programming mode, but not in simulation mode?

   In the simulation mode, some system resources are occupied to support the simulation functionality. The situation is not 100% same as the real programming running environment. If you have doubts about the simulation result, then please switch to ISP programming mode. Under circumstances, I suggest the use of programming–experiment mode.

6. How to do if I want to use 2051 single chip?

   Compared with 89S51 chip, 2051 is only lack of p0 and p2 port. The programming model and the instructions are both the same. So you can use 2051 chip as your wish only need to pay attention to avoiding the use of p0 and p2 port. If you must use 2051, then we can offer you other programmers with a discount.

7. Is 89S52 totally same as 89C51?

   89S52 is an upgrade version of 89C51 and their instruction set is completely compatible, and can substitute for each other. Compared with 89C51, 89S52 has the advantage of lower price and longer life expectancy. At the same time, 89S52 is configured with the watchdog and ISP downloading functionality.

51tracer debugger simulator  FAQ

Why the connection cannot be established under simulation mode?

1. USB driver may have not been setup successfully. Please check if it is OK at: control

panel\system\hardware\device manager. If you can see the COM port number information shown like below photo. If not, please reinstall the USB driver or change to another PC and have a try: sometimes, if the USB port number is changed, USB driver should also be reinstalled.

2 Simulation needs KEIL uv2 version 7.0 or higher version, ( Note some early version is not compatible), also the software must be installed under C:\ root directory, can not be other directory! When creating new file, DO NOT save it in other directory, also no Chinese character file name. Please strictly follow [1-8 ascii char].xxx filename style.

3 Make sure the COM port selection is correct (If it is a new system that have not been installed other USB device before, then the COM number should be COM3). Because simulation and programming both need COM port, so when doing simulation, please close XLISP programming or other similar debugging software that may occupy some COM port.

4. Make sure the simulator is reset well. Please press down the reset button. We can find a single green flash and a sound from speaker and this means the system is reset. When assert a long press on the reset button(more than 3 second), we can find continuous green flash and two sounds from speaker, this means the system is running offline.

5. Check if the oscillation frequency is setup OK. One an only one frequency can be set.

6. Check if the simulator cap insertion direction is correct. Pay attention to make the first PIN of the cap(red) align to first pin of the CPU. If the direction is invert, the system may become hot and light is dusky. Please change the direction immediately.

7. Your target board may not works well, maybe no correct clock and reset on it. You can test it by burning a program into the chip, if the burning is OK, it means the target board is correct.

8. Need extra power for target board?

Simulator cap could provide 5v/500ma power supply for the target board, in case, it is enough. If you fell it is not enough, you can provide an extra 5V power by yourself. The system is designed for protecting it from too high voltage power supply.

9. Why some port is not active?

Maybe the simulator cap connection is not tight. If possible, please unpack the simulator and have a measure on it by a multimeter.

10.Is the clock and reset of the target board is still functional?

When using 51TRACER simulator, the clock and reset of the target board is taken over by the simulator.

11. Why the program is not stable?

Please insert one line before main() function if C code:

     char code dx516[3] _at_ 0x003b;

Please Skip interruption vector area until 0050H if ASM code, like:

     org 0000H
     ljmp main
     org 0050H
     main：....;  program starting point

If you do not follow above instruction, when loading program, the simulator will generate “dididi”alarm sound and the simulation result maybe not correct.

As the development of the single chip machine technology, 00~40H is occupied by more and more new registers, not the original 00~30H. If your program is still 30H, please adjust it to 40H or 50H, 80H. If you have any question about it, please refer the program examples in the CD, they are all tested.

12. If cannot make certain what is wrong with it, please long press down the reset button to offline running mode. If the program still does not work well, please check your program.

13. If you want to simulate 2051, please refer to the pin definitions of 2051 and 51 and try to make an interface adaptor. Usually, we suggest you just use the 51 simulation and avoid the resources that not exist in 2051.

Below is the photo of simulator-XL2000 connection

(connect USB to PC, simulator to target board, note the frequency)