This DPI module provides a “virtual” JTAG connection between a simulated chip and OpenOCD. It makes use of the remote_bitbang JTAG driver shipped with OpenOCD, which forwards JTAG requests over TCP to a remote server. The dmidpi module is instantiated in the hardware simulation to receive the JTAG requests from OpenOCD and drive DMI pins directly.
Note that this module replaces the JTAG Debug Transport Module (“DTM”) inside the debug system.
|------------| |------------| |--------------| | | | | | | | | TCP intf | | DMI intf | | | OpenOCD |<========>| dmidpi |<========>| Debug Module | | (remote | | (DTM) | | | | bitbang) | | | | | |------------| |------------| |--------------|
The remote_bitbang protocol is documented in the OpenOCD source tree at doc/manual/jtag/drivers/remote_bitbang.txt, or online at https://repo.or.cz/openocd.git/blob/HEAD:/doc/manual/jtag/drivers/remote_bitbang.txt