For the SPI flash that cannot erase.

[usbbdm]

When you are programming the SPI flash but cannot find out why (even ISP), there are some additional step you might need to check.

What I found is that when erase and program, there is more rigid requirement for the power supply. A lot of time we simply solder wire on it with our own wire. We need to stable the power. Here is what I did to make it work. Solder a 220uF and 0.1uF between 3.3v and GND.



Please try and report back your test result.