SDRAM board

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

Moderators: Mug UK, Zorro 2, Greenious, spiny, Sorgelig, Moderator Team

guvner
Atariator
Atariator
Posts: 25
Joined: Sun Dec 09, 2018 12:32 am

Re: SDRAM board

Postby guvner » Sun Sep 08, 2019 10:31 am

ShyBry wrote: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.

Same here, anything above 130 will give errors instantly with the new memtest. Good thing, the cores don't go that high :D

lolof
Atariator
Atariator
Posts: 25
Joined: Sat Oct 06, 2018 9:21 pm

Re: SDRAM board

Postby lolof » Sun Sep 08, 2019 11:42 am

Here was perfect @167Mhz

Now it's working @140Mhz on my 32MB xs 1.1 board, above I have also instantly mistakes.

What is the blue number near the green one ?

When you say "better results with mixed caps", is there a special order to solder them or we can randomly solder the 3 different values among the board ?

Thanks
Last edited by lolof on Sun Sep 08, 2019 11:45 am, edited 1 time in total.

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Sun Sep 08, 2019 11:43 am

lolof wrote:What is the blue number near the green one ?

detected SDRAM size: 0- none(assumed 32MB), 1 - 32MB, 2 - 64MB, 3 - 128MB

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Sun Sep 08, 2019 11:48 am

Old SDRAM controller in memtest was unusual. It was using full page burst and thus almost didn't test the address bus. Cores don't use such SDRAM mode but single or up to 8 words burst. New SDRAM controller is similar to those used in cores and more reflects the real work. So less chance for case when you see 167MHz pass in memtest but have problem in the cores.

sawf01
Atari User
Atari User
Posts: 33
Joined: Sun Mar 11, 2018 9:05 am

Re: SDRAM board

Postby sawf01 » Mon Sep 09, 2019 6:04 am

Its good that we've got something that tests the boards properly, it did seem strange that every board could flawlessly pass at theoretical maximum so easily. The boards I've got that previously passed 167 now only get zero errors at 140, but they only get the odd error every five minutes or so at 160. At the end of the day the test is just a number, as long as it passes above the usable level it doesn't really matter, I've never had any noticeable problems in cores with any of my boards.

terminator2k2
Retro freak
Retro freak
Posts: 15
Joined: Sat Dec 22, 2018 10:23 pm

Re: SDRAM board

Postby terminator2k2 » Mon Sep 09, 2019 1:30 pm

On the new single pcb is it just the 3 aurdino connections which are wired to +v, A11 , A12 ?

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Mon Sep 09, 2019 2:14 pm

terminator2k2 wrote:On the new single pcb is it just the 3 aurdino connections which are wired to +v, A11 , A12 ?

yes

sawf01
Atari User
Atari User
Posts: 33
Joined: Sun Mar 11, 2018 9:05 am

Re: SDRAM board

Postby sawf01 » Mon Sep 09, 2019 4:01 pm

Just to check as I can't find it anywhere but is AS4C32M16SB-6TIN the recommended chip for the xsd and xs v2.2 as the pdf doesn't seem to state it on the xs v2.2?

terminator2k2
Retro freak
Retro freak
Posts: 15
Joined: Sat Dec 22, 2018 10:23 pm

Re: SDRAM board

Postby terminator2k2 » Mon Sep 09, 2019 4:05 pm

Sorgelig wrote:
terminator2k2 wrote:On the new single pcb is it just the 3 aurdino connections which are wired to +v, A11 , A12 ?

yes


ive wired a 64MB chip on an older xs pcb with the wiring according to the diagram and its not recognised

so 1 x XS pcb with 32MB and a modified XS with a 64MB chip and no go

modified 64MB works fine on its own in the first slot

no worries.....sorted

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Mon Sep 09, 2019 5:43 pm

why you re-wire it?
Old SDRAM version is supported too.

terminator2k2
Retro freak
Retro freak
Posts: 15
Joined: Sat Dec 22, 2018 10:23 pm

Re: SDRAM board

Postby terminator2k2 » Mon Sep 09, 2019 6:11 pm

experimenting, for 2 pcb ram setup , so i can play with 96MB neogeo

User avatar
gojira54
Atari User
Atari User
Posts: 38
Joined: Mon Oct 29, 2018 5:40 pm

Re: SDRAM board

Postby gojira54 » Mon Sep 09, 2019 6:46 pm

Thanks for releasing the SDRAM XSD board for MiSTer v2.4 =]
The schematic references 1uF capacitors, but in this thread it was recommended >It's better to use mixed set of caps 10uf, 1uf, 0.1uf - at what positions please?
Please do not take it personal, my lawyer has policies

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Mon Sep 09, 2019 8:56 pm

gojira54 wrote:at what positions please?

this is needed to be discovered

culexus
Atarian
Atarian
Posts: 6
Joined: Wed Jan 09, 2019 7:49 pm

Re: SDRAM board

Postby culexus » Tue Sep 10, 2019 9:03 am

So ordered some new boards and when they do get in on my bench I will do some testing with different caps.

As I understand there is not yet clear what caps to use at each positions.
I marked the pcb from C1-C12 and will report back so anyone wondering will easily follow the same layout.
So if anyone else is doing testing it would be nice if we used these markings.


Thanx. :)

SDRAM XS-D v2.4 Caps.png
You do not have the required permissions to view the files attached to this post.

JohnBlbec
Atarian
Atarian
Posts: 1
Joined: Tue Sep 10, 2019 9:40 am

Re: SDRAM board

Postby JohnBlbec » Tue Sep 10, 2019 9:48 am

Hello,

I'd like to make and solder MiSTer SDRAM XS v2 128MB (I don't plan to sell them) but i'm not sure what PCB impedance i should use. I've decided to make PCB in JLC. What PCB impedance do you recommend, please?

1) JLC7628
2) JLC2313

Thanks for your answer,
JB

User avatar
gojira54
Atari User
Atari User
Posts: 38
Joined: Mon Oct 29, 2018 5:40 pm

Re: SDRAM board

Postby gojira54 » Tue Sep 10, 2019 10:45 am

My parts are only just ordered so will take a few weeks before I can make up the small batch - will update =]
Thanks!!
Please do not take it personal, my lawyer has policies

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Wed Sep 11, 2019 2:32 am

JohnBlbec wrote:Hello,

I'd like to make and solder MiSTer SDRAM XS v2 128MB (I don't plan to sell them) but i'm not sure what PCB impedance i should use. I've decided to make PCB in JLC. What PCB impedance do you recommend, please?

1) JLC7628
2) JLC2313

Thanks for your answer,
JB

i've used JLC7628

merlin4782
Atarian
Atarian
Posts: 5
Joined: Thu Oct 25, 2018 9:49 pm

Re: SDRAM board

Postby merlin4782 » Sat Sep 14, 2019 1:38 am

sawf01 wrote:Its good that we've got something that tests the boards properly, it did seem strange that every board could flawlessly pass at theoretical maximum so easily. The boards I've got that previously passed 167 now only get zero errors at 140, but they only get the odd error every five minutes or so at 160. At the end of the day the test is just a number, as long as it passes above the usable level it doesn't really matter, I've never had any noticeable problems in cores with any of my boards.


This has been my experience also with the new memtest. Good to know it is more comparable to core performance.

ovalfastlx
Atariator
Atariator
Posts: 19
Joined: Sat Nov 03, 2018 3:13 am

Re: SDRAM board

Postby ovalfastlx » Sat Sep 14, 2019 3:31 pm

is the IC at U3 at SC or SOT?

Thanks

Sorgelig
Ultimate Atarian
Ultimate Atarian
Posts: 5078
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: SDRAM board

Postby Sorgelig » Sat Sep 14, 2019 4:35 pm

ovalfastlx wrote:is the IC at U3 at SC or SOT?

Thanks

any

sofakng
Retro freak
Retro freak
Posts: 12
Joined: Mon Sep 16, 2019 12:47 pm

Re: SDRAM board

Postby sofakng » Mon Sep 16, 2019 12:48 pm

EDIT: Nevermind. I've went ahead and purchased boards from JLCPCB (both XS and XS-D).

What are the recommended modules for 128 MB? Do you need the XS-D board for 64+64 MB for 128 MB or are there single modules that work on the XS board for 128 MB?

retronerd
Atarian
Atarian
Posts: 2
Joined: Tue Oct 23, 2018 8:37 pm

Re: SDRAM board

Postby retronerd » Mon Sep 16, 2019 6:46 pm

I just put in an order of SDRAM XSD board for MiSTer v2.4. wich Sdram chips is best to use?

culexus
Atarian
Atarian
Posts: 6
Joined: Wed Jan 09, 2019 7:49 pm

Re: SDRAM board

Postby culexus » Mon Sep 16, 2019 9:00 pm

I ordered AS4C32M16SB-7TCN since it looks to be good on price but as I understand you can use AS4C32M16SB-7TIN and AS4C32M16SB-6TIN also.
6TIN will be the fastest with 166Mhz but it is not needed for the Mister. I hope Im right :) The 7TCN is the comercial standard (143Mhz) and will be good for opration temps from 0°C to 70°C.

And for the U3 I ordered the SN74LVC1G04DCK 5-SC70.

For the caps I got some X7R 0805 with the value of 0.1uF, 1uF and 10uF. Still no news on how to configure them so it need to be tested when the parts get on the bench.

retronerd
Atarian
Atarian
Posts: 2
Joined: Tue Oct 23, 2018 8:37 pm

Re: SDRAM board

Postby retronerd » Tue Sep 17, 2019 8:52 am

culexus wrote:I ordered AS4C32M16SB-7TCN since it looks to be good on price but as I understand you can use AS4C32M16SB-7TIN and AS4C32M16SB-6TIN also.
6TIN will be the fastest with 166Mhz but it is not needed for the Mister. I hope Im right :) The 7TCN is the comercial standard (143Mhz) and will be good for opration temps from 0°C to 70°C.

And for the U3 I ordered the SN74LVC1G04DCK 5-SC70.

For the caps I got some X7R 0805 with the value of 0.1uF, 1uF and 10uF. Still no news on how to configure them so it need to be tested when the parts get on the bench.


Thanks! I tought you only need 0.1uf caps? is the 2x20 (40 Pos.) Female Header, Double Row, Right Angle, the same as Before? Thanks

culexus
Atarian
Atarian
Posts: 6
Joined: Wed Jan 09, 2019 7:49 pm

Re: SDRAM board

Postby culexus » Wed Sep 18, 2019 7:21 pm

retronerd wrote:
Thanks! I tought you only need 0.1uf caps? is the 2x20 (40 Pos.) Female Header, Double Row, Right Angle, the same as Before? Thanks


If you look back at the post sorgelig postet at page 9 he is mention that the use of mixed caps is better. This is decoupling caps and so far I have not found any good configuration. But I will mix and see how it goes :)

For the female header it is the same I used on my first 32mb board (SDRAM XS v1.1 by Sorgelig) 2x20 (40 Pos.) Right Angle.

I got my boards in to day and have done some soldering but is still missing the U3 and some 10uF caps.. :( Have to wait before I can do any testing.


Return to “MiSTer”

Who is online

Users browsing this forum: No registered users and 5 guests