Is it possible to use MSP430-JTAG-TINY-V2 to work with MSP430F2232 via SWB bus ?

Started by RB, April 25, 2023, 03:22:46 PM

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RB

Could you help?

Is it possible to use the MSP430-JTAG-TINY-V2 emulator to program/data
read the MSP430F2232 MCU via its SWB bus?

We have the assembled and working right PCB board with the MSP430F2232
SWB programming interface connector on the PCB.

There is no JTAG connector on the PCB.

Please see (the lnik to the pictute below) the programming interface schematic fragment of that PCB.

If it is possible... can you say what the signals of the MSP430-JTAG-TINY-V2 emulator output connector can be used for this?

And what will be necessary for this additionally (maybe)?



The schematic fragment mentioned is here:

https://prnt.sc/7sTf5NZemufQ


RB

Thank you.

Are the "P_IN" and "P_OUT" components - jumpers or switches or so?

What is the main intention of those components?


When each of them should be connected (shorted) during work?

LubOlimex

Are the "P_IN" and "P_OUT" components - jumpers or switches or so? What is the main intention of those components?

These are not located on the MSP430-JTAG-TINY-V2 debugger, but are located on your board. These are usually jumpers that control whether your board gets powered from the tool, or from another source. They prevent short-circuit between target's power supply and debuggers power supply. At least one of them has to be connected. You can check how it is in the schematic I previously shared:

https://www.olimex.com/Products/MSP430/Header/MSP430-HG2231/resources/MSP430-HG2231-schematic.pdf

The MSP430 debugger leaflet has similar jumpers recommended called J1 and J2.
Technical support and documentation manager at Olimex

RB

Would you please answer the questions:


1. As it is seen on this circuit:

https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg

There are the C2 capacitance present.

But as it is wrote: "C2 is NOT a capacitor...".

What is the information source claims the C2 is not capacitor?


The document "MSP430 Hardware Tools User's Guide (Rev. AH)", page 22

https://www.ti.com/lit/ug/slau278ah/slau278ah.pdf

states that:

"The typical value for SBW communication is shown. The range can vary between 0.1 nF and 2.2 nF
depending on SBW speed, voltage, and board design. See the device-specific data sheet for device-specific recommendations."

It semms that "C" is the capacitor yet?


2. What is the main intention of the R2/47KOms resistor placed on the TEST line?

https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg

And does that resistance value seem too much (maybe) for this needs?


Regards,
RB

LubOlimex

Yeah, don't take just the first part out of context read it as a whole "C2 is not a capacitor that you add to the circuit", this notice is here because else everyone would add 2.2nF to their circuit which would be a mistake. The guy that wrote it 15 years ago was not a native speaker, but probably the whole diagram should've been made differently with C2 (optional) and values 0.1nf up to a maximum of 2.2nF. The spirit of what is written is the same as what is written in Texas guides for SBW, aka:

"The device #RST/NMI/SBWTDIO is used in 2-wire Spy-Bi-Wire mode for bidirectional debug communication with the device and that any capacitance attached to this signal may affect the ability to establish a connection with the device. The upper limit for C2 is 2.2nF."

TEST/VPP is used when you blow fuses. R2 protects the TCK line of the JTAG when you blow fuses. Blowing fuses require high voltage. If you don't intend to blow fuses, you may skip connecting TEST/VPP and R2 altogether.
Technical support and documentation manager at Olimex

RB

Thank you.


I am not native english speaker too.


And the frases confusing are:

"The typical value for SBW communication is shown. The range can vary between 0.1 nF and 2.2 nF
depending on SBW speed, voltage, and board design. See the device-specific data sheet for device-specific recommendations."

If I would want to specify (in the documentation) the maximimum allowable capaitance on that line I will write clearly: "the maximum allowable capacitance of the RST/NMI line is 2200pf".

And not more!

There is wrote not clear on this subject in the guide "MSP430 Hardware Tools User's Guide (Rev. AH)", page 22.

RB

*TEST/VPP is used when you blow fuses. R2 protects the TCK line of the JTAG when you blow fuses. Blowing fuses require high voltage. If you don't intend to blow fuses, you may skip connecting TEST/VPP and R2 altogether.*

Is that said for the R2 resistor from here?:

https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg


or for the R2 resistor from that scmematic?:

"MSP430 Hardware Tools User's Guide (Rev. AH)", page 22, Figure 2-2

https://www.ti.com/lit/ug/slau278ah/slau278ah.pdf


The R2 used on those schemaics in different places and lines.


The question 2 from the post #4 is about R2 that based on this schemaic:

https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg

What is the main intention of the R2/47KOms resistor placed on the TEST line?

And does that resistance value seem too much (maybe) for this needs?

LubOlimex

I am writing only for our design and resource. When I say R2 I mean the R2 from this:

https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg

The value of R2 is not variable. There are only two options for the TEST/VPP line and R2:

1. (default) If you are planning to burn fuses you connect TEST pin/wire and place R2 47kOhm

2. (optional) If you would never blow MSP430 fuses of that board and target, then skip connecting TEST pin/wire altogether and everything on that line.
Technical support and documentation manager at Olimex

RB

I am trying to I unerstand everything right.


**TEST/VPP is used when you blow fuses. R2 protects the TCK line of the JTAG when you blow fuses. Blowing fuses require high voltage. If you don't intend to blow fuses, you may skip connecting TEST/VPP and R2 altogether.**

As it can be seen here ("MSP430 Hardware Tools User's Guide (Rev. AH)", page 22, Figure 2-2,
https://www.ti.com/lit/ug/slau278ah/slau278ah.pdf) -

"Note C
R2 protects the JTAG debug interface TCK signal from the JTAG security fuse blow voltage that is supplied by the TEST/VPP pin during the fuse blow process. If fuse blow functionality is not needed, R2 is not required (populate 0 Ohms) and do not connect TEST/VPP to TEST/SBWTCK".

But those manual words are referred to the R2 connected to the JTAG connector pin 7 (TCK!, not to the TEST pin).

The R2 serves here to protect as you wrote.

But it is "other" R2 (compared to the OLIMEX design) and is in other place (JTAG/pin 7/TCK).

And there is no its R2 on your design (https://www.olimex.com/Products/MSP430/JTAG/_resources/SPY-BI-WIRE-CONNECTION.jpg)

Why so?


Let's read furher along (Figure 2-2):

"Note D
For applications that are particularly concerned with excessive noise or ESD, a 500-? to 1-k? pulldown resistor can be added to the TEST pin, while still allowing proper programming of the target device."

The R2 from that OLIMEX circuit is that similar resistor from the Note D.

But its intention is protect the TEST line from any EMC issuies, not from fuse blowing.

(It is the reason of my question about R2 high (47khoms is too much to protect from noises) value.


Are there some mistakes in my understanding?

LubOlimex

Technical support and documentation manager at Olimex

RB


I understand that you want to say.


The SWB interface used in our design.

Not standard 14-pin JTAG.


Whether will be it erroneous to use such SWB MSP430 programming schematic pictured at that link?

https://prnt.sc/7sTf5NZemufQ

This circuit used in working device.

But it is unknown about programming-debug rig used by its designers...
 

Could you check this simple design circuit?

There is no 47k resistor on the TEST line to ground.

It does mean that TCK line be unprotected (as you wrote)?

The scheme should provide fuse blowing.