Proper circuit for programming PSoC 5LP using an external microcontroller? | Cypress Semiconductor
Proper circuit for programming PSoC 5LP using an external microcontroller?
I'm designing an remote PSoC 5LP programmer (like the MiniProg 3, except taking in data from a network), using the Serial Wire Debug interface, and I'm having a hard time getting the PSoC5LP chip to respond to any commands.
I first decided to port the document project AN73054 to a language understandable by the host microcontroller using a bottom-up development method (lowest level functions first). I failed to get any acknowledgments back from the SWDIO signal early in development.
After that, I've decided to borrow another PSoC 5LP board, compile the AN73054 project on there, and program the the target PSOC 5LP board. I wired the signals directly from the host PSoC 5LP output (SWDIO, SUDCK, and XRES) to the target PSoC 5LP board, and I kept getting errors. I soon discovered that all of the SWD signals from the target board were floating without any kind of response to any signal (it was floating between 2.5 and 3.1 volts), so I figured that a circuit is needed for programming the PSOC 5LP, even though the document said nothing about setting up a proper circuit (or any floating signals or pullup/pulldown resistors).
I then followed this guide, which revealed that I should pull down SWDCK to ground and pull up SWDIO to VCC. I tested this with both 3.3 voltage and 5 voltage sources from the host PSoC, with no avail.
To clear things up, both the PSoC 5LPs are intefaced with the CY8CKIT-050 development board. Both of the chip models are the same (CYC5868AXI-LP35). I read the development kit guide, the device programming specs, and obviously the AN73054 document. I don't think any of these documents gave any PSoC programming circuit examples (except for the last page in the programming specs, but that just showed how to wire up the PSoC power sources, which I think the development kit already covered). I also wired both boards properly (VDDA to VDDD, and VSSA to VSSD). I tried looking up any example PSoC 5LP programming circuit examples, but the schematics for any third-party programmers along with the Miniprog3 were unavailable, and any searches came up with nothing. I don't know what I'm doing wrong. Could you please help me with coming up with a circuit? Sorry for the long message and any percieved rudeness, I'm new here.