I bought one cheap chinese CH341A serial memory programmer black PCB (see attached picture). Someone already did the schematic of this board (atached). Source: All Vcc connections in the ZIF socket are 3.3V but the CH341A is powered at 5V. So all I2C and SPI signals are 5V while the external memory is powered at 3.3V. There are no limiting series resistors on those signals. One simple solution to fix this issue is to simply bypass the 1117-3.3V regulator. I can use the hot air station to remove the 1117 and then short-circuit the input with the output. My question is, is it safe to just do the short-circuit without removing the 1117 linear regulator? How do I write to SPI flash memory? Into is a programmer that can do in-circuit programming of the SPI Flash. For some of Atmels AT45xxxx serial flash. User can erase, program, verify and read content of SPI EEPROM and Flash. Search chip part numbers in the ISP programming software to view operation hint. If you are simply looking for a way to program the Winbond SPI flash with 'pre-loaded' data that your microcontroller would read for use when it is running then what you will want to look into is a programmer that can do in-circuit programming of the SPI Flash chip. This also known as in-system-programming (ISP). One choice is the. This USB connected device can program in circuit if you design your board correctly. They even sell an adapter clip that can attach into the SOW-16 package without having to design in a separate programming header on your board. DediProg has application information bulletins available to help with correct design for in circuit use. The main strategy for the design is to find a simple way to isolate the SPI interface drivers in your MCU system so that they do not interfere with the drivers in the SPI programming pod. The simplest way to do this is to put series resistors in the MCU driven lines between the MCU and the SPI Flash. The programmer would connect on the SPI flash side of the series resistors. Alternate methods could include adding a MUX or analog switches in the driven interface lines. An even more clever scheme is to add a 'programming enable' input to the MCU that makes the software disconnect all the SPI I/Os from the SPI Flash chip (i.e. Make all those GPIOs as inputs).
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November 2018
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