SDRAM board

https://github.com/MiSTer-devel/Main_MiSTer/wiki

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tomywong
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Re: SDRAM board

Postby tomywong » Thu Aug 29, 2019 9:36 am

Hi Sorgelig,

I use SDRAM XS v1.1 board with 64MB SDRAM chip AS4C32M16SB-6TCN. I soldered two board. Both are only pass 90mhz to 100mhz. I read your post, you use AS4C32M16SB-7TCN. It can pass 167mhz. So, AS4C32M16SB-7TCN is more compatible with MiSTer ? Thanks.

THaase
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Re: SDRAM board

Postby THaase » Thu Aug 29, 2019 9:41 am

The 6T can pass 150-160MHz (at least this is what happens in my case), but some problems around 130MHz (might be solveable with clock phase).
167MHz with the 7ns version is theoretically not possible als they are specified for 7ns -> 143MHz.
The 7T I'm having here (but didn't have had any time to solder them and do some investigations.

tomywong
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Re: SDRAM board

Postby tomywong » Thu Aug 29, 2019 10:05 am

Hi THaase,

Thanks for reply. I use the same board with Winbond chip (32M), it can pass 150-160mhz. But use AS4C32M16SB-6TCN with it, it can only pass arround 90-100mhz. Don't know what's the problem. If board is bad, why Winbond chip can pass 150-160mhz ? It is strange. Maybe I buy the bad chip ?

THaase
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Re: SDRAM board

Postby THaase » Thu Aug 29, 2019 2:08 pm

I‘m using 1uF capacitors for both (Winbond 32MB and Alliance 64MB) while Alliance 32MB are fine with 0.1uF.
Cleaning them with IPA afterwards from Flux.

tomywong
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Re: SDRAM board

Postby tomywong » Fri Aug 30, 2019 12:32 am

Hi THaase,

Thanks for the hints. I've some 1uf capacitors here. I'll try it and report here. :D

tomywong
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Re: SDRAM board

Postby tomywong » Fri Aug 30, 2019 10:42 am

I just replaced all capacitors to 1uf. But it is same. Maximum speed still about 100mhz. Maybe I need to try -7 model.

THaase
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Re: SDRAM board

Postby THaase » Fri Aug 30, 2019 10:49 am

Drag soldered?
Try pin by pin - specially if it‘s ROHS.

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Fri Sep 06, 2019 12:58 pm

Some notes about XSD module:
- It's 4-layers board.
- Layers order: Top(GTL), G1, G2, Bottom(GBL)
- 74LVC1G04 can be SOT23-5 or SC70-5. Footprint is universal. I prefer SC70-5
- It's better to use mixed set of caps 10uf, 1uf, 0.1uf
- Do not use XSD board for single chip module. It works, but timings aren't good. Use XS v2.2 which is in-line with XSD.

Both new XS and XSD modules now a little higher but they are lower than 10mm FAN on I/O board. So size of fully assembled MiSTer won't change.
Now modules have notches for easier extraction.

Both modules are of v2 standard and requires all SDRAM cores releases from mid-July or later. Modules have no arduino pins and compatible with future MiSTer expansion to dual-SDR version. Do not plug SDRAM to other 40pin connector now. Cores will need update to support new framework.

Doozer
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Re: SDRAM board

Postby Doozer » Fri Sep 06, 2019 2:28 pm

Hi Sorgelig,

Just to confirm XSD version 2.4 layout of pin 9 and 10 (on the 20x2 header), DQ14 and DQ15 are inverted compared to XS 1.1 and 2.2. Is this correct?

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Fri Sep 06, 2019 3:01 pm

swapping inside groups DQ0-DQ7 and DQ8-DQ15 is acceptable. So i do it if routing is better.

lolof
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Re: SDRAM board

Postby lolof » Fri Sep 06, 2019 6:35 pm

On the pdf from XSD 2.4 board, it's written "AS4C16M16SA-6TCN‎".

AS4C16M16SA-6TCN‎ = 32MB from old board

Should be AS4C32M16SA I think. There is also AS4C32M16SB...

-6TN is not available. -7 does the trick ?

EDIT : AS4C32M16SB-6TIN available...

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Fri Sep 06, 2019 7:34 pm

Yeah, it's obviously must be 32M16 part.
I will correct it.

Frederir
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Re: SDRAM board

Postby Frederir » Fri Sep 06, 2019 7:40 pm

I do not think anybody appreciate enough the beauty of the hardware design for the new SDRAM board. The PCB layout is fantastic, but the logic behind combining the two sdram chips is simply wonderfull.

culexus
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Re: SDRAM board

Postby culexus » Fri Sep 06, 2019 9:27 pm

I will order some PCB when you get them uploaded to PCBway :)

zerohimself
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Re: SDRAM board

Postby zerohimself » Sat Sep 07, 2019 6:06 am

i'm not sure you meant to leave your full name on the silkscreen. Was that a mistake?

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Sat Sep 07, 2019 8:58 am

zerohimself wrote:i'm not sure you meant to leave your full name on the silkscreen. Was that a mistake?

Can I leave my name on device i've developed?

zerohimself
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Re: SDRAM board

Postby zerohimself » Sat Sep 07, 2019 10:13 am

lol you know what i mean.. the internet can be rude sometimes.. :roll:

Frederir
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Re: SDRAM board

Postby Frederir » Sat Sep 07, 2019 11:15 am

I'm checking price for AS4C32M16SB-6TIN and I did not find anything under $11, does anybody has a secret cheaper source ?

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Sat Sep 07, 2019 12:13 pm

Frederir wrote:I'm checking price for AS4C32M16SB-6TIN and I did not find anything under $11, does anybody has a secret cheaper source ?

why it should be under $11?

lolof
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Re: SDRAM board

Postby lolof » Sat Sep 07, 2019 6:45 pm

If you have them for $11. You can alredy be happy I think.

If you buy a lot. You'll have them under $11 :-)

ShyBry
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Re: SDRAM board

Postby ShyBry » Sat Sep 07, 2019 8:36 pm

Is it expected for memtest_20190907 to have different test results than memtest_20180313? Is the newer version more strict?

With a 32MB SDRAM board, I can run 20180313 at 167MHz for several minutes without errors. But 20190907 fails immediately at any speed above 130MHz.

JimDrew
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Re: SDRAM board

Postby JimDrew » Sat Sep 07, 2019 10:21 pm

I have been paying just under $7 each set (128MB) at 500 pcs. $11 should be the 100 piece pricing.
Last edited by JimDrew on Mon Sep 09, 2019 6:45 pm, edited 1 time in total.
I am the flux ninja

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Sun Sep 08, 2019 12:34 am

ShyBry wrote:Is it expected for memtest_20190907 to have different test results than memtest_20180313? Is the newer version more strict?

With a 32MB SDRAM board, I can run 20180313 at 167MHz for several minutes without errors. But 20190907 fails immediately at any speed above 130MHz.

Release notes say "More traditional SDRAM controller for more adequate results"
It means less false "167MHz pass".

TWINKYTWONKA
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Re: SDRAM board

Postby TWINKYTWONKA » Sun Sep 08, 2019 7:22 am

is the xd ram board compatible with 2 of the 32 mbit chips to give a cheaper 64 mbit option?

thanks

Sorgelig
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Re: SDRAM board

Postby Sorgelig » Sun Sep 08, 2019 7:53 am

TWINKYTWONKA wrote:is the xd ram board compatible with 2 of the 32 mbit chips to give a cheaper 64 mbit option?

thanks

no


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