Serial Wire Debug (SWD) is a 2-pin electrical alternative JTAG interface that has the same JTAG protocol on top.

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Can you safely “short circuit” 2 signals when they compete for the same pin to avoid having to use a multiplexer?

I'm developing for a very limited, 8 pin LPC810 microcontroller and have to connect multiple signals on a single pin. Obviously, if there's only 1 output signal on a bus, that should be OK, but what ...
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64 views

SWD and i2C hardware layer differences

Both I2C and SWD are two-wire protocols. I wonder what are the main differences of the hardware layer of these protocols and what are the pros/cons of each one? It's also interesting that the maximum ...
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STM32 - two errors in turns during programming

I'm trying to program STM32F107VCT6 via SWD and I'm constantly getting two errors in turns (literally): Error: Connect failed, check config and cable connection ...
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139 views

How to daisy chain SWD Debug port

I have multiple mcu's that are configured to communicate with bus topology. I have 10 pins (4 of them is occupied by now) I need to debug (update firmware online, etc) all of these mcu's. I read this ...
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73 views

JTAG/SWD Data Logging

I would like to automatically poll and log certain memory locations on the STM32 I'm working with through the j-link debugger I am using to debug the system. Is this possible through the JTAG or SWD ...
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Embedded Pi JTAG program cable

I bought an Embedded Pi as an add-on for my Raspi. Seems that I should have also bought the ColinkEx programming cable too. I happen to have a Northmicro Blaster JTAG cable from when I was working on ...
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OpenOCD w/ ARM-USB-OCD-H+ARM_JTAG_SWD

Has anyone been able to debug/program using SWD over a Olimex USB-JTAG programmer and the ARM-JTAG-SWD adapter? If so, please share how you did it :) Specifically, I'm looking for what the OpenOCD ...
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Relationship between reset pins and SWD functions (ARM Cortex M0)

On many microcontrollers or other devices without JTAG/SWD functionality, there is a reset pin which when low unconditionally and asynchronously forces everything into a known state. On devices with ...
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Laying out a 10-pin JTAG/SWD connector on a final design

I'm designing a board with an ARM microcontroller on it (LPC1347FBD48) and I want to include a 10 pin jtag/swd connector, as is standard, for in-circuit debugging of my final design. Here is the ...
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JLNINK(SWD)+IAR can not debug stm32: communication error

guys. I am using J-link with SWD interface to debug my STM32F103VCT6 in IAR. I can enter download and debug mode but I can not use "step over" or "stop" function. Once I use one of them I will get ...
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JTAG vs SWD debugging

Skimming through this article I'm just wondering, what are the benefits of SWD debugging over JTAG debugging? I understand SWD uses less wires/pins, takes up less space etc. But how does it play out ...
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363 views

Finding an affordable integrated USB MCU

I'm in the early stages of designing a development board around Cypress Semiconductor's PSoC 3 and 5 range of chips. Much like the Arduino, I'd like the programming experience to be very easy, and ...
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416 views

SWD debugging solution

I'm planning to start a project based around a Freescale Cortex-M0+ chip. Apparently the M0+ is SWD only and does not support JTAG. I've been looking around, but I can't find much in the way of SWD ...
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214 views

generating a custom half duplex 1 wire serial protocal

I want to use a microcontroller from NXP to generate a SWD (Serial wire debug) serial signal. A SWD signal is a clock and a host to target header, a single cycle wait period, followed by either a host ...
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Debugging STM32LF1xx low-power behavior

Is there any practical way to use a SWD-based debugger such as those made by Segger to debug a program for the STM32LF1xx which uses low-power modes and sets the clock speed very slow? The debugger ...