82-000760-01 Datasheet, PDF (22/44 Pages) Analog Devices – HPUSB USB and HPPCI Emulators

JTAG Frequency Selection
JTAG Frequency Selection
USB-ICE emulators, high-performance PCI-ICE, and high-performance
USB-ICE emulators support a JTAG clock operation up to 50 MHz.
 Not all frequencies listed above are supported for all processor fam-
ilies. The displayed frequencies depend upon the processor family.
There is a relationship between the JTAG frequency and core clock fre-
quency of the processor. Typically, the core clock runs at a frequency that
is more than 2x the JTAG clock’s frequency. On newer Analog Devices
processors, the core clock is a variable that sometimes is set by switches or
software.
 If the core/JTAG clock relation is not followed, scan failures can
prevent the emulator from connecting to the processor.
Use the JTAG Frequency Selection dialog box to test and change the rate
at which the JTAG Test Clock signal (TCK) runs. To access the dialog
box:
• CrossCore Embedded Studio users choose Target > Settings >
JTAG Frequency Selection after launching a debug configuration.
• VisualDSP++ users choose Settings > JTAG Frequency Selection
after creating a debug session.
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HPUSB, USB, and HPPCI Emulators User’s Guide