One cannot precisely set the JTAG speed in
ispVM.
The port speed depends on many factors, including the PC speed and the type of cable used (parallel port, USB or USB2). We run as fast as we can.
Though we have no control over the exact speed,
ispVM System provides an option to slow the TCK for debug or noisy environments:
Select Project menu -> Project Settings -> Advanced -> TCK Low Pulse Width Delay
Set this value to 1 for fastest possible speed, or set to 2 or more to add delay.