Platform Cable USB II
DS593 (v1.2.1) March 17, 2011
9
iMPACT Cable Status Bar
A status bar on the bottom edge of the iMPACT GUI (
) provides information about cable operating conditions. For
example, if the host port is USB 2.0, Platform Cable USB II connects at Hi-Speed and the status bar shows usb-hs. If the
host port is USB 1.1, Platform Cable USB II connects at full-speed, and the status bar shows usb-fs. Finally, the status bar
displays the active cable and TCK_CCLK_SCK frequency.
Status Indicator
Platform Cable USB II uses a tri-color status LED to indicate the presence of target voltage and to indicate that a cable
firmware update is in progress (
When the cable is connected (using a ribbon cable, or flying leads) to a mating connector on the target system, the status
LED is illuminated as a function of the voltage present on pin 2 (V
REF
). Users must design their system hardware with pin 2
attached to a voltage plane suppling the JTAG, SPI, or Slave Serial pins on the target device(s). Some devices have
separate power pins for this purpose (V
AUX
), while others have a common supply for both V
CCIO
and the JTAG pins (TCK,
TMS, TDI, and TDO). Refer to the target device data sheet for details on JTAG, Slave Serial or SPI pins.
The status LED is amber when any one or more of the following conditions exist:
•
The cable is not connected to a target system
•
The target system is not powered
•
The voltage on the V
REF
pin is
≤
+1.3V.
The status LED is green when all of the following conditions exist:
•
The cable is connected to a target system
•
The target system is powered
•
The voltage on the V
REF
pin is
≥
+1.5V.
Note:
There is 200 mV of hysteresis in the V
REF
detection circuit. If V
REF
drops below 1.3V, the status LED turns amber and does not
turn green until V
REF
is raised above 1.5V.
The status LED is red whenever a cable firmware update is in progress.
X-Ref Target - Figure 7
Figure 7:
iMPACT (10.1) Cable Status Bar
DS593_07_021908
