scan_dr_hw_jtag command specifies a scan pattern to be scanned into the JTAG interface target data register. The command targets a
hw_jtag object which is created when the
hw_target is opened in JTAG mode through the use of the
open_hw_target -jtag_mode command. When targeting the
hw_jtag object prior to shifting the scan pattern specified in the
scan_dr_hw_jtag command, the last defined header property (HDR) is pre-pended to the beginning of the specified data pattern. The last defined trailer property (TDR) is appended to the end of the data pattern.
scan_dr_hw_jtag command returns a hex array containing captured TDO data from the
hw_jtag, or returns an error if it fails.