CC3220SF-LAUNCHXL: Programming through external UART and external XDS110

You got a detailed answer to how to program this device in https://e2e.ti.com/support/wireless-connectivity/wifi/f/968/t/864165. What is new in this post compared to the original one? 

Hi Jan,

I've done the testing but I was confuse about the RST pin.

Refer to the swra568 chapter 5.4 and "CC3220SF_Sch.pdf" from here.

I connected the GND and UART(Tx/Rx) between LAUNCH-CC3220MODASF and CC3220SF-LAUNCHXL as below.

LAUNCH-CC3220MODASF(XDS110) <---> CC3220SF-LAUNCHXL (CC3220SF)
==============================================================
XDS_UART_TX <---> J6.2(P57_GPIO_02) (i.e. CC3220 UART_RX)
XDS_UART_RX <---> J5.2(P55_GPIO_01) (i.e. CC3220 UART_TX)
GND <---> GND

[Fig_01] J6.2 of CC3220SF-LAUNCHXL

[Fig_02] J5.2 of CC3220SF-LAUNCHXL

There is no problem.

And the connection of RST pin. I think that it should be as below:
(J3.9)XDS_nRESET <---> J3.10(CC_nRESET) (i.e. CC3220 P32 RESET)

But it doesn't works!!

[Fig_03] J3 CC_nRESET of CC3220SF-LAUNCHXL

[Fig_04] CC_nRESET to P32  of CC3220SF-LAUNCHXL

[Fig_05] CC_nRESET pin  of CC3220SF-LAUNCHXL_1

[Fig_06] CC_nRESET pin  of CC3220SF-LAUNCHXL_2

I have to change the connection as below and it works.

[Fig_07] CC_nRESET pin  of CC3220SF-LAUNCHXL_3

Is the pin mapping of RESET pin between [Fig_03] and [Fig_05] right?
or...did I misunderstand the pin mapping?

Hi,

Connection of reset looks OK. But your UART connection is not correct. At XDS-110 side you need to connect top UART pins at other board you need to connect centre pins.

Jan

Hi Jan,

Yes, I connected the UART pin between top pin of UART (XDS-110) and centre pin of UART (CC3220SF_LAUCHXL).

But for the Reset pin, I want to confirm that which one is correct?

1) At XDS-110 side: top reset pin, and at CC3220SF_LAUCHXL side: bottom reset pin

2) At XDS-110 side: bottom reset pin, and at CC3220SF_LAUCHXL side: top reset pin

thanks

Hi,

From your images it looks that you have connected UART centre pins at both boards.

Pins next to TM4C chip (XDS-110) are always related to XDS-110 itself. That means output from XDS-110 is a top pin. Proper connection is first point.

Jan

Hi Jan,

That's a misunderstanding, and not what I meant.

Both [Fig_06] and [Fig_07] are the same board (same side) with two different settings.

First, I set the  CC3220SF-LAUNCHXL as [Fig_06] but it doesn't work.

then I change the RESET pin as [Fig_07] and it works.

According to the [Fig_03], I regard the CC_nRESET pin is J3.10.

so I connected as [Fig_06]. but as I mentioned above, it doesn't work. I don't know why?

by the way, actually my setting of XDS-110 side is the following and it's correct:

Hi Jan,

This is what I felt confused.

If the purple wire of [Fig_06] is XDS-110 reset pin, and the pin map should be:

but it's upside down with the pin map in [Fig_03].

or did I refer to the wrong schematics? (http://www.ti.com/lit/df/sprcag0a/sprcag0a.zip)

Chunyu

Hi Jan,

According to the schematics, and I rotate the pin map figure.

and the order from left to right is: RST, TMS, TCK, TDO and TDI.

I thought that the pins will be as below:

The schematic shows that the upside is CC side, and you say the upside is XDS-110.

It doesn't match and it's what I felt confuse. Is the schematic wrong?

(by the way, the result of testing also shows that the upside is XDS-110)

Chunyu

Hi Chunyu,

No. Schematic is correct. Maybe it could be better if jumper symbol will be rotated but important at schematics are labels of signals.

This schematics from TI is a pretty good and easy for understanding. At my career as the embedded developer I saw much, much worse schematics. I am pretty surprised that this very easy schematic can confuse anyone.

Jan

Hi Jan,

Thanks, that's my misunderstanding.

In order to avoid more misunderstanding could you please tell me how to distinguish that?

If I got a schematic and a board like below, how do I distinguish and make sure that which one is [CC_nRESET] or which one is pin_1?

Is there any mapping rule?

thanks.

Chunyu

Hi Chunyu,

It is a good practice to draw schematic symbol similar like looks real package. But at real world, it may not be there. Let's take an op-amp symbol. Does it look like a real package?

It is part of your job and responsibility as the developer to figure out how schematic symbol is mapped to real package. And when you are not sure, just take multimeter and measure your real hardware.

Jan

Hi Jan,

thanks for your patient reply.

I'll try harder for these aspect.

Chunyu