LPC55S69 : wakeup due SPI3

[EugeneHiihtaja]

Hi !

SPI3 can be used as wakeup source for exit from PowerDown mode. And it works fine.

But RX fifo has size 8 items only and wakeup take > 350 us.

It means , MCU can't receive any more bytes until SPI ISR can be processed.

So I shouln't expect if more than 8 items will be in Fifo until exit from PowerDown is fully completed.

Is this so ? Or for wakeup more RX fifo can be allocated some how ?

Regards,

Eugene

[xiangjun_rong]

Hi, Eugene,

You are right that the maximum FIFO size of LPC55S69 SPI module is 8, this is hardware restriction, no way to increase the SPI FIFO size.

If more than 8 data rush into the SPI FIFO before the exit from power-down is fully completed, some data will be lost.

Hope it can help you

BR

Xiangjun Rong