STA8089GAT - BOOT pins settings

[Dror]

I do not understand how to properly boot from SPI as it contradicts the BOOT table in the guide document for the STA8089GAT pins on page 22 (“STA8089GA-Pin-by-Pin-guideline.pdf�?).

To boot from SPI we need a pull up on BOOT0 which has an internal pull down according to the same document.

The same for BOOT1, according to the table it should be “1�? in boot from SPI and it has an internal pull down.

Could you please explain what are the correct setting for STA8089GAT device boot? Is the document an error?

Does it mean we need to force BOOT0 to GND on production for first firmware programming and then place a pullup on it?

[Francesco Virlinzi · Accepted solution]

Hi

STA8089GAT has 4 special pins (BOOT0,1,2,3) which are able to trigger different mode during power-on.

• Booting from SPI/SQI => BOOT[3:0] = 0111
• Booting from UART => BOOT[3:0] = 0110

In your design you must be able to manage both the configuration:

• Booting from UART is required to program del Chip in the production line (to program the flash)
• Booting from SPI/SQI is the standard application booting from flash (wen flash has already been programmed)

Hope this helps

Regards

Fracensco

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