RGH Dual Nand - How does demon solve the SB trace cut problem?

GadgetCat

Full Member
Dec 6, 2011
29
0
Hi there, so Im researching to make a dual nand, but now they release DemoN and take the hard work out of it for me..
My own dual nand solution has a manual switch, I havent tried to reprogram the coolrunner and run a wire from the sync switch yet, but my main issue is:

How have they solved the CE select problem? pull CE high and 0Volt to VSS to the NAND and is should go into standby, while provide 3.3v to VSS to NAND2?

The demon picture they have provided looks like a simple QSB for the bottom of the board, with FT1T1-8, power and ground from C1T2, and on the demon QSB itself by the NAND VSS is a SMD chip to ground.. is this all the HW required, apart from the clever sw they are going to put on the IC to remove the need for the NANDX..

Sorry, wouldnt let me post in DemoN forum, im too noob..
 

ceckin

Full Member
Apr 29, 2011
25
0
According to Cygons:

Cygnos said:
Pin number 9 is marked in red as it carries the NAND-flash’sCE-signal (chip enable). This pin has to be lifted up from its cor-responding pad because Cygnos 360 needs to control when theon-board NAND-flash is enabled. In the Xbox 360, the CE-signalis normally driven by the south-bridge. Leaving this pin connectedto the pad would require Cygnos 360 to drive the signal againstthe south-bridge’s output transistor. The risk of ultimately dam-aging this transistor due to excessive heat build-up and thus de-stroying the whole console was unacceptable for us. We thereforetook the technically superior way of lifting up the CE-pin.
So probably a workaround was found, as DemoN and 360Squirt doesn't require trace cut.
 

Mister_X

VIP Member
Apr 13, 2011
189
0
Canada
All cygnos did was pull sb standby power low for a moment when the switch posion for the active nand changes. That clears the cached smc i the sb. im sure tx figured that out quite easily.

Sent from my SGH-T989D using Tapatalk
 

ceckin

Full Member
Apr 29, 2011
25
0
I believe you confuse the SMC reset with CE, you have to reset SMC always in order to re-read the SMC from the newly selected nand, but you can't select the second nand with simple smc reset. If im not mistaken they pull down the SB CE to GND (0V)(ofc not directly) and put 3.3V on the second CE.
 

Mister_X

VIP Member
Apr 13, 2011
189
0
Canada
I believe you confuse the SMC reset with CE, you have to reset SMC always in order to re-read the SMC from the newly selected nand, but you can't select the second nand with simple smc reset. If im not mistaken they pull down the SB CE to GND (0V)(ofc not directly) and put 3.3V on the second CE.
Obviously they have to power the new nand when its switched to. I'm not confused i just left the obvious out.

From what i can tell on the SB pinout i have seen and the tests i have done with my oscilloscope, when the nand is switched, obviously 3v3 is switched to the appropriate nand when the switch position changes and SB reset pin, is pulled low (0v) from 3v3. this causes the Sb to reset and the smc to be reloaded from the newly activated nand.

I can also say if TX can design the products they do, they have no issues figuring out this process and probably do the same SB reset on nand switch.
 

2615863

VIP Member
Nov 30, 2011
552
33
Tampa,FL
The only way to see exactly how they did it is when its released
 

wty4ka

Full Member
Jan 10, 2006
81
0
Coventry, UK
can i get a simple wiring diagram for this no trace cut method
edit: sorry for resurecting an old thread, found the link via google.
 
Last edited:

v0rtex

Full Member
Apr 19, 2010
62
0
Athens, Greece
sorry for being slightly off topic but I don't want to start a new thread for this...and the previous one got derailed...

From all the rumors on DemoN I gather it's an all-in-one-solution...and thats great
if someone is installing it himself, isn't very good with soldering and doesnt already own an spi programmer for example.
For the majority of end-users though, who only care about the price... since they're paying for the product AND someone to install it for them it's not.
I think that's why it was frowned upon on the other thread as far as the price goes...
What i'm getting at is if it would be wiser to have that in mind when designing these products.

I remember someone argued (on irc i think) : "It will cost as much as a retail game" , meaning the price is nothing compared to what it delivers, and I agree 100%. Stop and think to whom you're saying this though.... your target group is people who mod their consoles to avoid having to pay the $xx for a game.
 

hersheys247

VIP Member
Dec 25, 2011
1,128
88
Detroit area, MI, USA
... your target group is people who mod their consoles to avoid having to pay the $xx for a game.
Well i disagree with this, first off piracy was never the intention, it was a means of playing back ups and homebrew, unsigned code on YOUR system.



If i helped you in anyway, please press the THANKS and REP button

Sent from my brain tumor causing device using Tapatalk
 
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