Hi Jan Thank you for the reply. I appreciate it.
> The reason for the (perhaps redundant) NOP operation might have been be to > collect the status of the preceding DMI operation - op field of the "dmi" > JTAG register. I agree this is used to retrieve the status of the previous DMI operation if the NOP function is used in scan_field->out_value. For JTAG driver developer like me, we push scan_field->out_value into the JTAG. Writing op field of zero, telling the device to not read/write the address indicated, is needed. The JTAG driver will replace scan_field->in_value with what is read from JTAG. Normally we just populate it with zeros, but since it is decided to populate with NOP I am presuming it there is a reason for doing so. May be to supply an indicator that the field was not written to yet. While it is not important for my purpose of “load <image>”, some other callers might be relying on this. >That is however just a guess, and as you noted, the data is not used anywhere. Thank you for the confirmation. > If you'd like to improve the code, you are welcome to post a patch to > https://github.com/riscv/riscv-openocd It will later be propagated here. Thank you for this information. It saved me another mailing list post to ask whether should I to go riscv-openocd or here. Many thanks and have a good weekend Cinly
