Project: HDMI/DVI out for STFM

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exxos
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Re: Project: HDMI/DVI out for STFM

Post by exxos » Sat Sep 01, 2018 10:34 am

Smonson wrote:
Sat Sep 01, 2018 8:52 am
I can't guarantee that the buffer will be fast enough for the 32MHz clock though, I recommend checking it on a scope before depending on it.
OK, what chip did you use ?
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Sat Sep 01, 2018 10:52 am

exxos wrote:
Sat Sep 01, 2018 10:34 am
OK, what chip did you use ?
74LVC245A
https://assets.nexperia.com/documents/d ... CH245A.pdf

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Re: Project: HDMI/DVI out for STFM

Post by poobah » Sun Sep 02, 2018 3:41 pm

Smonson wrote:
Sat Sep 01, 2018 10:52 am
exxos wrote:
Sat Sep 01, 2018 10:34 am
OK, what chip did you use ?
74LVC245A
https://assets.nexperia.com/documents/d ... CH245A.pdf
Have you guys looked at the IDT QuickSwitch devices?

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Sun Sep 02, 2018 4:20 pm

poobah wrote:
Sun Sep 02, 2018 3:41 pm
Have you guys looked at the IDT QuickSwitch devices?
I'm using them :)
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~

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Re: Project: HDMI/DVI out for STFM

Post by troed » Sun Sep 02, 2018 4:37 pm

Smonson wrote:
Sat Sep 01, 2018 10:52 am
exxos wrote:
Sat Sep 01, 2018 10:34 am
OK, what chip did you use ?
74LVC245A
https://assets.nexperia.com/documents/d ... CH245A.pdf
Seems plenty fast according to that spec sheet, unless I'm misunderstanding something.

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Sun Sep 02, 2018 4:57 pm

troed wrote:
Sun Sep 02, 2018 4:37 pm
Seems plenty fast according to that spec sheet, unless I'm misunderstanding something.
I think it was just a suggestion..Nothing wrong with those of course.

For my stuff, I am pushing every MHz out of everything, so the IDT switches have pretty much zero delay, which is what I need. In case of the FPGA stuff, a few ns isn't going to make any odds. Though I guess the IDT stuff may be easier to solder as they (IIRC) are larger packages.
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~

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Re: Project: HDMI/DVI out for STFM

Post by poobah » Sun Sep 02, 2018 8:18 pm

exxos wrote:
Sun Sep 02, 2018 4:57 pm
... Though I guess the IDT stuff may be easier to solder as they (IIRC) are larger packages.
Yup, I solder them by hand fairly easily.

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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Mon Sep 03, 2018 12:30 am

The only reason I mention the buffer is that the one I used for the 16MHz line (M74VHC1GT125DF2G) can't hack it at 32MHz. Since 16MHz is not too fast by today's standards I didn't worry about it when selecting buffers.

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Re: Project: HDMI/DVI out for STFM

Post by rpineau » Mon Sep 03, 2018 1:01 am

May I suggest the NB3N551 for clock buffering :

https://www.mouser.com/datasheet/2/308/ ... -83648.pdf
Working ones : MegaSTE (68020) / TT030 / Falcon with AB040 & Eclipse / 1040STF
Need testing : Falcon with CT2

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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Mon Sep 03, 2018 1:15 am

Suggestions are welcome. But from the datasheet it looks like this device is only guaranteeing to produce a 2.4v high. Dunno if the Atari would be too happy with that.

But this is definitely the kind of thing I should have used in the first place

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