How to implement long delay with SPI-RAM in ADAU1452

Hello Liang,

Will you be selfbooting the part from SPI EEPROM or do you have a system controller?

Dave T

Hello Liang,

There is a delay cell you can drag into your schematic.

The "MAX" input box sets the maximum delay. I am not sure what the units are at this point. It was due to be changed. It might be in bytes instead of words. With a word being one sample period. I asked this question recently to the programming team and have not heard back.

The "CUR" setting is the runtime setting for the delay. This will be from one sample period to the max.

Click on the "Z-n" box to open up the setup for the SPI RAM. You have to make sure it does not conflict with the bootup EEPROM address.

Dave T

Hi Dave T,

I would like to know what 1452 supports off-chip SPI RAM.Please recommend one or two ICs to me.

Thanks

Chen

Hello Chen,

We have used the 23LC1024 for SPI RAM. We did not do a large test of many different vendor's products. But, we did test this Microchip product.

Dave T

Hello Dave,

My application used a system controller for ADAU1452.

Can I use the external SPI RAM?

Thanks,

Jeff

Hello Gundang,

Yes, but only if the SPI RAM is only used by the ADAU1452.

The ADAU1452 has two communications ports. The slave port is what the system controller will use to communicate with the ADAU1452 and to program it. The master port will communicate with the SPI RAM as a master so nothing else can be using the RAM.

Dave T

Hello Dave,

is it possible to get a project file for the ADAU1452, using SPI RAM and SPI-communication with a system controller ?

Best

Michael

Hello Dave,

You have done tests with the 23LC1024. Is it possible to get your project file for the ADAU1452 ?

Best

Michael

Hello Micheal1,

No, I have not. These tests were done by another engineer when the part was being developed. I will try to get something together for you but it will take me a little while.

Dave T

Hi Dave

I have seen old posts saying that the ADAU1452 external SPI ram is 16bit?

and that there were plans to make it 24bit

Can you advise what the current status of this is.

Is there a drawing to show how to connect the external SPI ram. does it use the "HOLD" pin on the ram chip? etc

Thanks

Brett

Hello Brett,

I think the old posts you are referring to are talking about I2C RAM and it is talking about address word size not data. For an I2C EEPROM we can only address 16 bits worth of addresses. We do not support the extension for the 17th bit at this time. For SPI there is not that limitation. We have 24 bits of addressing.

I will attach a drawing that shows how we connected a SPI EEPROM onto the master port. I think this should answer your questions.

Thanks,

Dave T