10 months, 2 weeks ago.

SPI ports P0_4, P0_5, P0_6, P0_7 wrong?

According to the MAX32625PICO MBED page, the SPIM0 is located at P0_4 for CLK, P0_5 for MOSI, P0_6 for MISO and P0_7 for SSEL. But in the MAX32625PICO datasheet on page 4/5 is given in table 3: P0_6 = SSEL, P0_5 = MISO, P0_4 = MOSI and P0_7 = SCLK. What is now correct? The same pin assignment as in the datasheet is also on the MAX2771EVKIT, for which I want to program the MAX32625PICO (which is placed on the evaluation kit). I found, that if I take the assignment according to datasheet from Maxim, the board will blink red because the assignment is considered to be invalid. In the file PeripheralPins.c (in TARGET_Maxim/TARGET_MAX32625), this assignemnt is listed in lines 109 following and after changing it there, I was able to operate without the red led blinking (which shows a runtime error according to Mbed doc). Now I would like to know which is the correct assignment and if there are other places in Mbed/target source code where I have to change the pin assignment, because I cannot see any output for the SCLK or SDATA in both pin assignment cases with an osi. Thank you!

Question relating to:

MAX32625PICO Programmable Interface Controller

1 Answer

10 months, 1 week ago.

Hi MB,

If my understanding is not correct, please let me know. You are building MAX32625 image and run it on MAX2771EVKIT. I checked their datasheet, they are using different chip so I don't think the image will work properly.

Regards, Desmond

Hi Desmond Chen,

I checked the MAX2771EVKIT datasheet (https://datasheets.maximintegrated.com/en/ds/MAX2771EVKIT.pdf) again and I think that U11 is the MAX32625PICO. What do you mean with a different chip? I have the hardware at hand and the MAX32625PICO is placed onboard the MAX2771EVKIT. Is this what you doubt? Please check the page 8 of the MAX2771EVKIT datasheet. I can access this board through pressing the button on the PICO board placed on the EVKIT. The board then appears as MAINTENANCE in the explorer and I copy the firmware to that USB storage device. Sadly, I cannot debug on the board as MBed Studio does not connected to the board. I have also tested the standalone PICO board, here MBed shows a different MAX board as target and not the MAX32625PICO. Is there any MAX32625PICO specific guide how to debug with MBed Studio without additional hardware? And regarding my original question: I ask about the difference in the PICO pinout for SPIM between the MBed document and the MAX datasheet (https://datasheets.maximintegrated.com/en/ds/MAX32625PICO.pdf, see p.4-5 for SPIM). Why is this different?

posted by M B 23 Aug 2019


Looking into the schematic, I think MAX32625 is used as interface MCU here, the target MCU is MAX2771.

Mbed Studio provides MAX32625PICO as a target, I can see that in version 0.5.3. No additional hardware is needed for debugging MAX32625PICO, just make sure you already update the firmware here.


The datasheet looks has two definitions, could you check that with Maxim? Since the platform and datasheet is from them, we are not able to give further comments of that.

And by the way, are you using our provided SPI examples?


Regards, Desmond

posted by Desmond Chen 23 Aug 2019

Hi, how should I debug if MBed Studio does not recognize the board but instead reports MAX32630FTHR?

posted by M B 23 Aug 2019

Hi, I don't have the board in hand so I am not able to test. But I think the why Mbed Sutdio can't recognize it mostly because the DAPLINK firmware is not updated, would you check that?

Regards, Desmond

posted by Desmond Chen 23 Aug 2019

Hi, I have downloaded the firmware again (max32625pico_daplink.bin default DAPLink image) and copied it to the target. In MBed Studio, I get the message "Would you like to set the connected device, MAX32630FTHR (MAX326...), as the active selection?". When I accept and click on "Debug program", I get the error message: "Failed to launch PyOCD GCB Server: Timeout".

posted by M B 23 Aug 2019

According to AN6350, the SPI configuration of the MAX32625PICO is right. The MAX2771EVKIT schematic must be wrong.

posted by M B 28 Aug 2019