VS1053 - Flash at the same SPI bus

[Victoria Nope]

Hello,

I have noticed a comment "Please read application notes before connecting FLASH to same SPI bus as VS10xx." in the example schematics (VS1053 datasheet, page 14). My question is, which application note should I read? I could not find one mentioning reason why to avoid this.

Thank you!

[pasi]

Hi,
It seems to refer to the "Connecting SPI Buses" (vs10XXan_spi.pdf) from http://www.vlsi.fi/en/support/applicationnotes.html .

Mostly, you have to reserve GPIO pins for all of the chip select signals.

Also, you should note that SD/uSD cards connected to the same SPI bus might produce issues, because they power up in the MMC/SD communication mode, which does not respect chip select. Thus removing and inserting the SD card will disrupt communication with the vs10xx until the communication with the card has been initialized and the card kicked into SPI communication mode.

[Victoria Nope]

Hello,

I see, so having two separate SPI buses is preferrable for no disruption of the communication with the vs10xx chip at card insertion or removal. That makes perfect sense.

Thank you very much for your prompt reply!
Best regards!