Datasheet STi5517SWA

[fmak]

I need the datasheet for this but ST keeps it a big secret and google doesn't help. Anyone else?

[rfbrw]

http://www.st.com/stonline/products/...27/sti5517.pdf

[fmak]

Originally posted by rfbrw
http://www.st.com/stonline/products/...27/sti5517.pdf

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I know, but his is not a datasheet with no pinout or application circuit!

[rfbrw]

Ask ST for the full datasheet or learn to reverse engineer.

[philpoole]

Hi fmak,

What do you want to use the 5517 for? It is a very dedicated STB chip and is not really suited to DIY.
I doubt ST would want to support you unless you were a major customer buying thousands of chips.
Plus, 5517 is nearly obsolete.

Sorry.

Cheers,
Phil

[fmak]

[QUOTE]Originally posted by philpoole
[B]Hi fmak,

What do you want to use the 5517 for? It is a very dedicated STB chip and is not really suited to DIY.
I doubt ST would want to support you unless you were a major customer buying thousands of chips.
Plus, 5517 is nearly obsolete.
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I want to get spdif out of a Pace digibox. The sound thru' the routing chip is pathetic, that from the dac not bad, but I want to tap the 5517 for Tx out. Can you help?

Why is Sky so powerful that most information on boxes is suppressed - the only way to get decent radio in Britain is thru Sky which transmits uncompressed digital audio. I assume that the country (thru' BBC) pays for this. Yet we cannot easilly obtain decent radio thru digiboxes. DAB (digital radio braodcast) is aweful due to too high a compression, yet consumers are being told that they have 'CD quality' which is not even as good as analogue radio)

[philpoole]

Hi Fmak,

Typically, these chips have a dedicated SPDIF pin. This is great, but has to be enabled in software.
If there is no SPDIF on the box, then there is a chance that the SPDIF pin is enabled (if it can be found), but it is slim I'm afraid.

If seperate DACs are being used then it should be possible to tap off the I2S feeding them to an SPDIF encoder (crystal or similar). That is probably your best bet.
I think SkyPlus boxes have SPDIF out as they support 5.1.
If you get really stuck, you should be able to buy one of these from a trade satellite stockist and get Sky to move your non Sky+ subscription over to it. Its technically possible, but whether Sky are keen is another issue.

Sky is very guarded about their hardware because there is a lot of clever stuff on board to prevent piracy, because they are pay per view. Its their bread and butter.

BTW their audio is compressed, it is MPEG 1 encoded, there may be less loss than with freeview, but it is manipulated to a point.

Hope this helps.

Cheers,
Phil

[fmak]

I think SkyPlus boxes have SPDIF out as they support 5.1.
If you get really stuck, you should be able to buy one of these from a trade satellite stockist and get Sky to move your non Sky+ subscription over to it. Its technically possible, but whether Sky are keen is another issue.

Sky is very guarded about their hardware because there is a lot of clever stuff on board to prevent piracy, because they are pay per view. Its their bread and butter.

BTW their audio is compressed, it is MPEG 1 encoded, there may be less loss than with freeview, but it is manipulated to a point.

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I read (HiFi news) that radio transmissions are 48/16. Is this not correct? Anyway I have managed to modify every digibox I own to give much better sound.

Can't be very good technology if they cannot even connect the audio out properly! On some older boxes, you can tap the dacs without going thru' these horrible routers. On those boxes with toslinks, these are not even engineered properly, with that horrible 27MHz clock that seems to drift so that a narrow pll relocker will not work.

What right has a private company censure proper access to State Radio such as BBC? Its Microsoft all over.

[philpoole]

Digital set top box is primarilly in the mass production arena.
It really isn't brilliant quality wrt hardware.
Mind you, I struggle to think of any compressed data signal that is any use compared to CD.
The drifting 27MHz clock is a factor of DVB. Its a vcxo controlled by signals from the broadcaster to ensure it is in tune (or as well as possible) with the 27Mhz clock to ensure AV sync.
Because you have audio and video data amongst other things, its not a simple case of just 'bung out the data as it comes in', there is a lot of reconstruction of data from packets because its all multiplexed in a sporadic manner. Because there is 10x more video data to audio it can get very out of sync, so trying to follow the broadcasters clock to present frames and 'audio snippets' is a solution to this syncing issue.

Not justifying the technology, but that's how it works.

I'm not sure what the compression ratio of audio is, it varies a lot, but its probably about 10:1. It obviously can be a lot more.

Cheers,
Phil

[philpoole]

Its a vcxo controlled by signals from the broadcaster to ensure it is in tune (or as well as possible) with the 27Mhz clock to ensure AV sync.


Sorry, should have read 'with their 27MHz clock'