Commits on Jun 20, 2024

1. [jtag,dv] Keep TCK running a short time after a transaction …

   This handles a rather confusing situation in the DMI frontdoor. The
   problem is that a DMI request has to travel from dmi_jtag to
   dm_top (involving a CDC from TCK to the main clock) and then back
   again (involving a CDC from the main clock back to TCK).
   
   If we stop sending JTAG operations in that time, the CDC doesn't
   actually get anywhere. The wait is jtag_agent_cfg_h.vif.wait_tck(10),
   which ends up waiting based on elapsed time rather than clock edges.
   
   The result is that when we send another JTAG operation to find out the
   result of the operation, the "busy" status only makes it through the
   CDC *after* the JTAG operation has finished and reported that the dm
   is idle.
   
   Things then get rather confused when the "busy" status appears, which
   the agent interprets as a mysterious operation that has just come into
   being.
   
   Signed-off-by: Rupert Swarbrick <[email protected]>

   

   rswarbrick committed Jun 20, 2024
   Configuration menu

   • View commit details
   • Copy full SHA for 12676f3
   • Browse repository at this point

   Copy the full SHA

   12676f3 View commit details

   Browse the repository at this point in the history