jtag_add_runtest() function
Goes to TAP_IDLE (if we're not already there), cycle precisely num_cycles in the TAP_IDLE state, after which move to @a endstate (unless it is also TAP_IDLE).
Arguments
num_cycles
Number of cycles in TAP_IDLE state. This argument may be 0, in which case this routine will navigate to @a endstate via TAP_IDLE.