What's this?

Thomas · 8th July 2002, 05:52 PM

I was wondering...

Does this chip have an serial i2s out? The datasheet are only the short version and it doesn't say clearly.

http://www.sonysemiconductor.co.uk/p...s%20CXP401.pdf

Any help are appreciated very much

haldor · 8th July 2002, 09:18 PM

Hi Thomas,

I didn't see any mention of I2C, but it is pretty easy to implement an I2C Master in software as long as you have two spare port pins.

An I2C Peripheral interface is a very different story. Then you need to use a maskable external interrupt pin to detect a start condition. Much more complicated and will consume a lot of the processors bandwidth (if there are other I2C peripherals on the bus).

What are you planning on doing that needs I2C? Are you going to control some I2C peripherals (easy to do) or do you want to become an I2C peripheral (more difficult without hardware support).

P.S. I implemented an I2C master in software on an 8052 running at 12 MHz and data transfers ran at about 40 KHz. If you need to run faster than that then either use a faster processor or a hardware implmentation of I2C.

Philips is the best source of I2C info (they have the patents on I2C). Checkout their website.

Phil

guido · 9th July 2002, 12:10 PM

Thomas,

Hard to say, from figure 1 there isn't any. From figure 2 maybe the datao/xlto/clko. It is probably some dig audio out, but if it is i2s or some other protocol used is hard to tell.

It is probably configurable via the CPU interface. You have to try to get more info.

On the other hand, the chip is used to make a 'one chip' solution for CD players, so you don't need the i2s interface anymore internally between dig filter+dac. So maybe there's only SPDIF for the normal digital out.

For the other reaction i2s != i2c..

Greetings,
Guido

haldor · 9th July 2002, 04:49 PM

Quote:

Originally posted by guido
Thomas,

For the other reaction i2s != i2c..

Greetings,
Guido

Sorry, I didn't read the inital post correctly, My BAD.

Phil

Elso Kwak · 9th July 2002, 05:07 PM

Hi Thomas,
Very probably it is Sony/Burr-Brown format as it is a Sony chip.

Thomas · 9th July 2002, 09:28 PM

Thanks

You have all been helpfull. I guess I have to get the full datasheet and or the service manual to be shure, but i dont' know where to find them.

I sort of didn't tell you first, but I wanted to know if I could connect a custom DAC not using the SPDIF.

Anyone know where I can get this:

CXP401 datasheet
Cambridge Audio D300SE service manual

Any service manual with a description of CXP401 could also be used.

Thomas

8th July 2002, 05:52 PM	#1
Thomas diyAudio Member Join Date: May 2001 Location: Right here	What's this? I was wondering... Does this chip have an serial i2s out? The datasheet are only the short version and it doesn't say clearly. http://www.sonysemiconductor.co.uk/p...s%20CXP401.pdf Any help are appreciated very much

9th July 2002, 12:10 PM	#3
guido diyAudio Member Join Date: Mar 2002 Location: diepe zuiden	Thomas, Hard to say, from figure 1 there isn't any. From figure 2 maybe the datao/xlto/clko. It is probably some dig audio out, but if it is i2s or some other protocol used is hard to tell. It is probably configurable via the CPU interface. You have to try to get more info. On the other hand, the chip is used to make a 'one chip' solution for CD players, so you don't need the i2s interface anymore internally between dig filter+dac. So maybe there's only SPDIF for the normal digital out. For the other reaction i2s != i2c.. Greetings, Guido __________________ GuidoB

9th July 2002, 05:07 PM	#5
Elso Kwak Banned Join Date: Dec 2001 Location: Zamboanga, City of Flowers, Mindanao	I2S? Hi Thomas, Very probably it is Sony/Burr-Brown format as it is a Sony chip.

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8th July 2002, 09:18 PM	#2
haldor diyAudio Member Join Date: Aug 2001 Location: Columbus, Ohio	Hi Thomas, I didn't see any mention of I2C, but it is pretty easy to implement an I2C Master in software as long as you have two spare port pins. An I2C Peripheral interface is a very different story. Then you need to use a maskable external interrupt pin to detect a start condition. Much more complicated and will consume a lot of the processors bandwidth (if there are other I2C peripherals on the bus). What are you planning on doing that needs I2C? Are you going to control some I2C peripherals (easy to do) or do you want to become an I2C peripheral (more difficult without hardware support). P.S. I implemented an I2C master in software on an 8052 running at 12 MHz and data transfers ran at about 40 KHz. If you need to run faster than that then either use a faster processor or a hardware implmentation of I2C. Philips is the best source of I2C info (they have the patents on I2C). Checkout their website. Phil

9th July 2002, 09:28 PM	#6
Thomas diyAudio Member Join Date: May 2001 Location: Right here	Thanks You have all been helpfull. I guess I have to get the full datasheet and or the service manual to be shure, but i dont' know where to find them. I sort of didn't tell you first, but I wanted to know if I could connect a custom DAC not using the SPDIF. Anyone know where I can get this: CXP401 datasheet Cambridge Audio D300SE service manual Any service manual with a description of CXP401 could also be used. Thomas