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JStamp Tutorials - Plug it together and access with JTAG

Connect the hardware, check target jumpers

Plug your tan DB25-to-RJ45 adapter into an available PC parallel port. Plug one end of the red CAT5 cable into the DB25-to-RJ45 adapter, and the other into the JTAG pod. Now plug the JTAG adapter into your JStamp development kit using the provided 10-conductor ribbon cable.

To execute from RAM (best for debugging), the swap memory jumper on your target should be installed.

Apply power to your development system and the green power LED on the JTAG pod should be lit.

Connect to JStamp with Charade

Now start up Charade - the aJile JTAG interface software. If there is a problem with the connection between your PC and JStamp, you will see the following error screen:

If you see this screen, check the items listed:

  1. Be sure the connectors are fully seated and that the DB25 adapter hasn't partially pulled out of your PC's DB25 connector.
  2. Your development station should be powered by an appropriate power source. The JStamp dev station has a power LED which will be lit when it is receiving proper power.
  3. charade.cfg is located in your aJile tools folder aJile/Charade. It contains a list of target devices to which you will connect, along with information about their chip selects, memory map, and ports on your PC. Here's a typical line from Charade.cfg:
    [DEVICE] ##### test equipment section
    LABEL= "aJ-80 (port 378)" # Label
    Note that Port 378 is the PC's address for LPT1. There is another entry for Port 278 which is LPT2. On startup Charade will search all available parallel ports and try to find one with a JStamp connected to it. The order of the [DEVICE] descriptions in charade.cfg is not important, however Charade lists the available devices in the order in which they appear in the file, and uses the first device as its startup default. It may be convenient for you to move your most-used device be first in the list of devices, then you won't have to manually change the device every time you start Charade.

  4. CharadeDrv is a parallel port driver and is automatically installed when you install the aJile tools. To see if it is running on Win2K Pro, click on Start->Programs->Accessories->System Tools->System Information. Click on Software Environment and you should see drivers in alphabetical order, like this:


    On XP, use Start->Settings->Control Panel->System->Hardware->Device Manager->. Then click View and select "Show Hidden Devices". Then scroll down to Non-Plug and Play Drivers and expand it. You should see CharadeDrv without any warnings. You can select it and right-click Properties to see the details (click the image for a higher-resolution one):


    If you don't see the driver installed, running, and OK, re-install the aJile tools with Administrator priveleges, reboot the PC and check again. I've personally had no trouble using Charade on NT4, Win98, Win2K Pro and XP Pro systems.
  5. Note that if you change any system setting, uninstall a driver, etc, you must reboot the PC between such changes. Don't try to uninstall and reinstall a driver without rebooting in between - Windows needs to start up in a given state before you change it, then reboot again so that it can start in the new state. Don't ask us why -- this is just our observation.

If Charade starts up and can connect to an aJile-powered device, you will see a normal startup screen:


Here you can see that the Charade device has defaulted to aJ100 which is *incorrect* for JStamp -- it should be aJ80. Change this by using the Device taskbar item. Don't worry about the "BIST Fail" message - this is normal when starting up without a valid program loaded into your device's RAM. Part of the Built In Self Test (BIST) checks for a valid program to run, so if there isn't one, the BIST Fails. Since we've just powered up and haven't loaded anything yet, we expect this message.

Try a "dump" of memory by typing "du" in the charade command window. You should see random data similar to this:

Using a different parallel port address for the JTAG adapter:
This is commonly done with notebook PCs such as the IBM ThinkPad, which has its parallel port at 0x3BC instead of the usual 0x378.

In \ajile\charade\charade.cfg, change any lines like this for any devices you intend to use. There's a [DEVICE] header for each hardware target such as JStamp, SaJe, JStik, etc. You want to change this line:

PORT_ADDR= 378 # base address (hex)

Change the PORT_ADRR to 3BC or whatever you need.

Then, in your notebook BIOS be sure the parallel port is enabled and set to bidirectional ECP. By default, the parallel port is often not enabled, or is set to a less-capable mode such as EPP or even a unidirectional mode. Charade wants an ECP parallel port.

Then be sure that CharadeDrv is installed and running.