Information: BCM20732S debug/trace capabilities through the HCI UART port

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MichaelF_56
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The BCM20732 supports the use of Serial Wire Debug (SWD) debug/trace messages that are output through the HCI UART port that's onboard. The SWD pins are muxed with HCI UART and are used in such a manner that the hardware and firmware can auto-detect the presence of SWD or the HCI host; this means that HCI based download and debugging are mutually exclusive of one another.

In order to use these debug/trace output facilities from the HCI UART, you would need to:

1.) Closest to the BCM20732S (note that the JP1 header resides on the other side of the FTDI USB to USB converter, so it will not work), create a set of jumpers to an external header that contains the following signals: SWCLK = HCI UART_TX, SWIO = HCI UART_RX (the SWD SWO signal is not supported)

2.) Set ble_trace_enable = 0 when initializing the application

3.) Once debugging is complete over SWD, return ble_trace_enable to its default state to enable downloads

Note: Setting ble_trace_enable = 2 will output printf style traces to the HCI uart, which will then interfere with the symbolic debugger over SWD.

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1 Solution

Unfortunately there is not an appnote available which shows how to setup a proper debugging environment within the existing SDK.

It looks like you learned about our upcoming J-Link capabilities within this thread: Re: How to debug the board step by step?

So were hoping that this will improve the debugging environment available within the WICED SMART SDK.

View solution in original post

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22 Replies
Anonymous
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What software would be required to set breakpoints etc using the SWD interface? Is this possible yet using GDB or whatever?

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The only supported symbolic debugger is ARM Real View debugger with ICE (or DStream with ARM DS5). GDB is not supported currently, but may be supported sometime in the future.

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Anonymous
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so I take it there won't be debugging in v2 of the SDK?

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SDK 2.0 will still support the ARM debugger, but not GDB yet.

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Anonymous
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Hi = You say "still" : is it possible to use the Real view ICE / DStream hardware debuggers with the WICED smart SDK 1.1 - (just not with the WICED smart tag board)? And not within WICED smart IDE - you have to use a proprietary piece of software (Real view/ DS5)?

It seems that DStream/ DS5 are the only ones that are on sale now?

Without registering etc- can anyone explain what can be used/ how much it costs to set up a proper debugger with the WICED smart development system?

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Yes, RV ICE/DStream cannot be used with WICED Smart IDE, you have to use ARM's RV Debugger or DS5. DStream and DS5 are the the current versions of ARM's debugging tools (they used to be called RV ICE and RVDS).

I believe ARM has different kinds of licenses that cover everything from a single seat to a site license. See DS-5 / Debug / DSTREAM | ARM Development Studio 5

Anonymous
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Are there any specific hardware modifications that need to be made in order to use SWD and the DS5 debugger? Is there an app-note or something that can describe how to set up a proper debugging environment using Broadcom 2073X devices?

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Unfortunately there is not an appnote available which shows how to setup a proper debugging environment within the existing SDK.

It looks like you learned about our upcoming J-Link capabilities within this thread: Re: How to debug the board step by step?

So were hoping that this will improve the debugging environment available within the WICED SMART SDK.

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Anonymous
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We are spinning our hardware and are planning on supporting the JLINK BASE debugger as has been described in several threads in this forum. We are looking to add a footprint for the JLINK 6-pin adapter.

According to this thread, only SWCLK and SWIO are brought out, muxed with the HCI UART pins, and the SWD SWO signal is not supported. What should we do with the SWO signal for the debugger? Should we tie it to GND? Should we pull it low or high? Should we leave it floating?


Thanks

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I believe it's ok to leave the SWO signal floating.

Note that the new TAG4 board will utilize the following 4-pin connector.

jlink.png

To complete the picture for J-Link based connectivity on the new TAG4 board, I wanted to include a picture of the attached connector (below) as well.

jlink-2.jpg

This is J52 and will exist as a standard 20 pin connector; SWDIO and SWDCLK go to the J-Link header described previously.

J52 is essentially a standard 20 pin JTAG connector and our 4-pin J-Link can connect to this connector via a cable we are creating that will bridge J-Link to the 4 pins we have on the tag (i.e. J52/20-pin on one side with J2/4-pin on the other side: PWR_VIO, SWDIO, SWDCLK and GND).

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Anonymous
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Does Broadcom have this adapter in place and working with JLINK BASE now, or is this a future implementation?

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We have working prototypes.  Once in production, we will make this an orderable PN.  We will also provide a schematic so customers can build their own.

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Anonymous
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Perfect. Thanks!

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Anonymous
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hello mwf_mmfae...

can this adapter be ordered by now?

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Unfortunately, it cannot as we never went to production with the adapter because so many customers were building them themselves with minimal difficultly per the instructions provided in this blog: WICED Smart J-Link Debugger

david_armour j.t

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Anonymous
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Thanks for the confirmation here Mike.

Regards

Dave

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Anonymous
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Thank you for the answer, even though it's not the answer I hoped for

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Anonymous
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Do you have an ETA for the J-Link adapter cable as an orderable P/N?

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I believe we are targeting having this added to the price book in September for release at the beginning of Q4.

Note that the schematic for the cable adapter to the J-Link 20 Pin connector is here on the blog as several people have made their own: WICED Smart J-Link Debugger

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Anonymous
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Any word on the availability of this JLINK 20-pin to 4-pin adapter? And whether it will work with the BCM20737TAG_Q2 board?

Thx-

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Unfortunately we do not have an update on when this cable will be available in production with an oderable part number. At this point, all we can offer is the schematic linked above. My apologies.

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