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When multiple blasters are installed, how does the driver make the determination of which one is -0 and which is -1, etc? Is it based on the order of initial driver installation?
My experience with multiple devices (each with a unique FTDI serial number) is:1)
after the initial installation and driver install, the devices always get assigned the same ID, regardless of the order of cable connection.
2) using Windows device manager to uninstall the driver for both devices and then re-plugging the cables won't swap the assignments
In order to change the assignements, do you have to delete registry keys and .inf files as well before re-installing in the desired order? Or are there registry keys that can be edited?
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I recently looked at this. Here's my observations.
1) Give the USB-Blasters unique serial numbers.
I have two Stratix IV GX development kits that I would like to use simultaneously; one as the transmitter and the other as the receiver. These boards ship with identical FTDI EEPROM serial numbers.
I reprogrammed the FTDI EEPROMs using FT_PROG (the updated version of MProg) and gave each board a unique serial number; S4GXDK01 and S4GXDK02.
Plugging the new boards into Windows XP created the following registry entries;
HKEY_LOCAL_MACHINE/CurrentControlSet/Enum/USB/Vid_09fb&Pid_6001/S4GXDK01
HKEY_LOCAL_MACHINE/CurrentControlSet/Enum/USB/Vid_09fb&Pid_6001/S4GXDK02
within those entries, the only thing that differs is the number at the end of the 'Driver' field.
2) Here's the observations under Windows XP
If S4GXDK01 is configured so that its factory default configuration does not get loaded, and S4GKDK02 does load, then "jtagconfig -n" can detect the two different designs (due to the different JTAG nodes detected).
a) Under Windows XP, if I plug either board in, then "jtagconfig -n" detects either board as "USB-Blaster [USB-0]".
b) If I plug the second board in, then "jtagconfig -n" detects two devices; "USB-Blaster [USB-0]" and "USB-Blaster [USB-1]".
Based on the output from jtagconfig -n, I can tell that [USB-0] is the board with serial number S4GXDK01, and [USB-1] is S4GXDK02.
The assignment of [USB-0] and [USB-1] stays the same regardless of the order I plug in the boards.
If your boards are in the wrong order from what you desire, I suspect the registry key "Driver" might be the entry being used to distinguish them. Try uninstalling a specific USB-Blaster and then plug it back in.
Cheers,
Dave
Honored Contributor
