Two SPI NOR Flash chips in parallel, possible?


#1

Hi
is it possible to hardware mod a router to have two spi flash chips , with different chip selects and mount them as one chip ? lets say two 4MB chips, and openwrt sees them as 8 MB ? or maybe sees the second chip as an mtd partition?
note: I'm fully capable of any hard / soft mod required.


#2

Not really, SPI means serial peripheral interface.

The select and clock are parallel but the io is serial

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#3

Sounds like you are looking for "mtd-concat". This feature is available for openwrt 4.14 and 4.19 and currently, some ath79 buffalo devices are already using it.


#4

If you hard to find one more CS pin you can use the same CS0 pin as C̅S̅1 (negative or reverse) by using single inverter gate.
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(But use NOR SPI Fash instead SD-Card)