JTAG-OpenOCD problem

[Zingemneire]

Hi,

We have developed our own board based on the ESP32-WROVER module and I am trying to get JTAG capability on it but something is preventing it from working correctly on my WINDOWS10 machine.

The hardware is a custom development board with the same FT2232H on it as on the ESP32-WROVER-KIT board.
The four JTAG connections from the FT2232H to our ESP32-WROVER module are a carbon copy of what is shown in ESP32-WROVER-KIT_SCH3, with the exception of the exception of the S_TDI arrangement shown in the JTAG section of that schematic.
Is that S_TDI circuit essential? If it is I can still add it.
I have checked out the hardware umpteen times and I am absolutely sure there are no shorts, no signal interruptions and all necessary pull-up and pull-down resistors. The four JTAG signals from the FT2232H ( TCK, TDI, TDO and TMS ) are definitely connected to the correct pins on the WROVER module.

The drivers for the TF2232H device all installed correctly and indicate proper functioning, in fact: the USB <=> serial port on channel B works perfectly. The standard driver for CHANNEL A was replaced with another one using the Zadig application as specified in the documentation.

The ESP32 version of OpenOCD is installed as it should and I use an msys32 script to start it, the only change compared to the standard "esp32-wrover.cfg" file is that I have lowered the adapter_khz value to 200 instead of 20000 hoping that that might solve something.

Code: Select all

#!/bin/bash
echo "Starting OpenOCD"
cd /C/msys32/home/ESPdev/esp/openocd-esp32
bin/openocd -s share/openocd/scripts -f interface/ftdi/esp32_devkitj_v1.cfg -f board/esp32-wrover.cfg

OpenOCD starts as expected but keeps reporting the following:

Starting OpenOCD
Open On-Chip Debugger 0.10.0-dev (2018-04-18-12:04)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
none separate
adapter speed: 200 kHz
esp32 interrupt mask on
force hard breakpoints
Info : clock speed 200 kHz
Error: JTAG scan chain interrogation failed: all ones
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: esp32.cpu0: IR capture error; saw 0x1f not 0x01
Warn : Bypassing JTAG setup events due to errors
Info : esp32: Debug controller was reset (pwrstat=0xFF, after clear 0xFF).
Info : esp32: Core was reset (pwrstat=0xFF, after clear 0xFF).
Error: cpu0: esp32_fetch_all_regs (line 165): DSR (FFFFFFFF) indicates target still busy!
Error: cpu0: esp32_fetch_all_regs (line 165): DSR (FFFFFFFF) indicates DIR instruction generated an exception!
Error: cpu0: esp32_fetch_all_regs (line 165): DSR (FFFFFFFF) indicates DIR instruction generated an overrun!
Error: Exception reading pc!


I trawled all through this forum, and anything else I could find on the internet, and it looks like everything should be OK but it is not.

I am really at the end of my wits now so any help/suggestion would be very much appreciated.

[Zingemneire]

Having read something about potential shorts on boards I checked out resistance between JTAg signals and ground/power supply. They all check out fine, consistent with installed pull down resistor (TCK) and installed pull-up resistors ( TDI, TDO, TMS ).

[Greg-R]

You have an official WROVER-KIT board and your Windows based OpenOCD script is working with that board?

Regards,
Greg

[Zingemneire]

Hi Greg,

To the best of my knowledge we don't but later today I will ask the person who has been running the project for quite a while now whether we have one or can get one.
It is an excellent suggestion to try it on an official board first, if it does work there then there must still be a subtle hardware difference between what I have come up with and the official board.

Many thanks,
Filip

[Zingemneire]

Yep,
One module will be ordered ASAP, it may take a few weeks before we actually get it because of internal administration etc... But I will keep everybody posted when we get to really testing it.

Bye for now.