Get/set JTAG frequency.
Get JTAG clock frequency for current scan chain.
jtag frequency -list
Get list of supported JTAG clock frequencies for current scan chain.
jtag frequency <frequency>
Set JTAG clock frequency for current scan chain. This frequency is persistent as long as the hw_server is running, and is reset to the default value when a new hw_server is started.
Current Jtag frequency, if no arguments are specified, or if Jtag frequency is successfully set. Supported Jtag frequencies, if -list option is used. Error string, if invalid frequency is specified or frequency cannot be set.