[WIZ750SR] I can not firmware upload (ISP mode)

WIZ750SR (W7500x) series provides dedicated ISP Downloader program. (ISP Downloader can upload firmware by using UART2.)
To download the ISP program, click “Using the ISP” to download it.
https://wizwiki.net/wiki/doku.php?id=products:wizwiki_w7500p:getting_started:write_firmware

First of all, if you can not download the firmware, check the checklist below.

  1. Is power supplied correctly?
    a. If only the module is powered directly, the recommended power supply should be up to 3.3V, 2A.(ex. USB port).
    b. If used with EVB, you can supply power using DC adapter (5V, 2A) or Micro USB. (ex. WIZ750SR, WIZ750SR-100, WIZ750SR-105)

  2. Did you check that the LD1(D1) RED LED lights when power is supplied?
    a. When power is supplied on the schematic, the RED LED should be lit unconditionally.
    b. If it does not light, there is a possibility that the power is not supplied or it is short-circuited. or check if the power is connected in reverse.
    c. In the latter case, the board becomes very hot, so turn it off immediately.

  3. Does it work in ISP mode?
    a. To connect to ISP mode, set the Boot pin of WIZ750SR (W7500x) to High (3.3V).
    b. You can connect to the ISP mode by holding the Boot pin high (3.3V) and pressing the Reset switch.
    c. At this time, be sure to press the Reset switch and check that the Boot pin is maintained at High (3.3V) at the same time.
    d. If this is not the case, try to keep the Boot pin high (3.3V) set and power turning it off and on again.
    e. If used with EVB, you can make the Boot pin high (3.3V) with the following settings:

    • For the WIZ750SR-EVB, you can use the Slide SW to make the Boot pin high.
    • In case of WIZ750SR-100-EVB, you can use the Tact SW to make the Boot pin high.