Can we interface CYW43455 VIO to 1.8V to run SDIO at 1.8V?

[PaAg_4627576]

Can we interface CYW43455 VIO to 1.8V to run SDIO at 1.8V? Yes, then how to configure SDIO for 1.8V operation at default starting from initialization?

Using Murata Module - LBEE5HY1MW-230

[Zhengbao_Zhang]

Hello:

would you please check below setting in the module ?

[PaAg_4627576]

Hello,

This not what I meant.

I need to understand how to make SDIO work directly at 1.8V when you are not using 3.3V. What are the configs and settings do I take care in driver or software?

[Zhengbao_Zhang]

No, I didn't find any special setting for 1.8V IO setting in the code.

Did you meet problems when trying to set the interface to 1.8V IO voltage ?

[PaAg_4627576]

Software team is concerned on initial requirement of 3.3V for initialization of SDIO before it switches to 1.8V. Which mode do you select to configure this in for initialization (first transaction) on 1.8V?

[Zhengbao_Zhang · Accepted solution]

Hello:

   So your concerns are :

a. 3.3v transfer to 1.8V ,   SDIO emulation will fail if we set a wrong voltage ?

b.  don't know how to set VDDIO on the device.

My answer are here:

1.  We only can set one voltage of IO, we will not change mode dynamically since it is a hardware strap pin.

2.  if final IO =1.8V,  set the device IO to 1.8v.

3.  if you really have concerns,   do not pull wl_REG_ON pin  before SDIO interface is stable.