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Understanding S5 switch on ADAU1701-MINIZ

Question asked by Artifex on Feb 5, 2015
Latest reply on Feb 6, 2015 by Artifex

Dear friends!

 

I'm quite new to the ADAU family of devices, so probably I'm going to ask some long-before-answered questions just due to lack of skills in web search, but, sorry, here it goes anyway)

 

While developing my design I'm wondering about the S5 switch on the ADAU1701-MINIZ evaluation board, eh, well) what's it for anyway?))) At first glance we need to set it in "down" position (towards the USBi connector) to set the WP pin low and enable writing to the EEPROM, but we need to set it high to allow the ADAU to self-boot. According to the datasheet at least. The page 27 of the datasheet says:

 

The ADAU1701 does not self-boot if WP is set low. Holding this pin low allows the EEPROM to be programmed in-circuit. The WP pin is pulled low (it typically has a resistor pull-up) to enable writes to the EEPROM, but this in turn disables the self-boot function until the WP pin is returned high.

 

But then I just left the switch in the down position and continued with programming and rebooting the board, and almost forgot that it's there, and it was (and still is) self-booting OK! Well, then I got back to my own schematics and... stumbled upon a question whether this switch is needed at all) So is it true that ADAU1701 (and ADAU1401A, which I am planning to use) is going to self-boot whatever the initial WP pin setting is?

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