AR# 38171: ML605 - Usability Errata Related to SMA Connectors
ML605 - Usability Errata Related to SMA Connectors
Xilinx has noticed some usability scenarios which may inhibit proper functionality of the ML605 development boards:
1) When an SMA connector is attached to J58 the JTAG connection stops working
In certain isolated scenarios SMA connectors can push against the metal can of oscillator X5. The metal can of this oscillator then pushes against the lower pin (pin 1) of jumper J40. Since the metal can of the oscillator is tied to GND, pin 1 of J40 becomes tied to GND. Tying this pin to GND interferes with JTAG functionality.
To avoid this problem, users can apply electrical tape to the side of the metal can of the oscillator to prevent electrical connectivity to J40. Users can also physically bend the pins of J40 to prevent them from touching the can of the oscillator. Additionally, it is possible to remove X5 oscillator prior to installing an SMA Cable onto J58, then re-install the X5 oscillator.
A close-up picture of this configuration is below, and is attached to this article:
2) An SMA connector cannot be properly fitted to J26.
The location of J26 is sufficiently close to the PCB carrier for the LCD module that it physically inhibits the proper installation of SMA connectors to J26. The LCD module can be temporarily removed to allow installation of the SMA connector and then re-installed. Spacing in this configuration is tight but functionally sound.