5:11 p.m.
Well My electrical engineering knowledge does not reach as far that I
would know where to connect what :) I can read a schematic and solder
based on that, but those pictures from the wiki that I linked,
http://www.coreboot.org/Developer_Manual/Tools/Dual_Flash has a small
PCB, with 2 flash chips on it, but I can't figure out where to connect what.
I do think it's a great idea, and maybe it would be an idea to draw the
PCB in kicad/geda or the like, and actually have small batches made. I
know dangerousprototypes.com has loads of small PCB's made for a few
bux. Having a few on hand of these, and be able to send them to people
would be great! Stuff one in an envelope and mail it out for the price
of a stamp.
On 06-03-12 09:55, Peter Stuge wrote:
Oliver Schinagl wrote:
Oh wow, that's some nice work there,
unfortunatly I only have 1 bios
socket on my motherboard(s) and would use have to 'stack' the bios
chips.
It works fine if you keep the switch wires very short.
Or you can build a transistor-based or IC-based switch circuit which
stays very close by, and then gets remote controlled by a switch on a
long cable.
//Peter 
5:22 p.m.
New subject: Dual SPI Flash
Oliver Schinagl wrote:
Well My electrical engineering knowledge does not
reach as far that I would
know where to connect what :) I can read a schematic and solder based on
that, but those pictures from the wiki that I linked,
http://www.coreboot.org/Developer_Manual/Tools/Dual_Flash has a small PCB,
with 2 flash chips on it, but I can't figure out where to connect what.
That's the simple mod with some photos showing the principle at
http://stuge.se/m57sli/
A variation to the concept is to have a switch pull down the HOLD#
pin to GND. This should also work fine as long as the switch is not
toggled while the flash chip is being accessed.
I do think it's a great idea, and maybe it would
be an idea to draw the PCB
in kicad/geda or the like, and actually have small batches made. I know
dangerousprototypes.com has loads of small PCB's made for a few bux.
I guess whoever made the PCB can publish source and gerbers so that
others can order the same board if they want.
//Peter
5:41 p.m.
New subject: Dual SPI Flash
On 06-03-12 10:22, Peter Stuge wrote:
Oliver Schinagl wrote:
That would be probably the best idea
to start with. I've been staring at
the foto of the pvb for a while, and did notice as you said, only one
pin is being diverted. Mrtadis is the one who uploaded the foto, his
user page on the wiki however is quite empty, other then mentioning
wanting to become a GSoC student.
Well My electrical engineering knowledge does not
reach as far that I would
know where to connect what :) I can read a schematic and solder based on
that, but those pictures from the wiki that I linked,
http://www.coreboot.org/Developer_Manual/Tools/Dual_Flash has a small PCB,
with 2 flash chips on it, but I can't figure out where to connect what.
That's the simple mod with some photos showing the principle at
http://stuge.se/m57sli/
A variation to the concept is to have a switch pull down the HOLD#
pin to GND. This should also work fine as long as the switch is not
toggled while the flash chip is being accessed.
I do think it's a great idea, and maybe it
would be an idea to draw the PCB
in kicad/geda or the like, and actually have small batches made. I know
dangerousprototypes.com has loads of small PCB's made for a few bux.
I guess
whoever made the PCB can publish source and gerbers so that
others can order the same board if they want.
//Peter
5:42 p.m.
New subject: Dual SPI Flash
Oliver Schinagl wrote:
So check which one and compare with the flash chip data sheet.
//Peter
I guess
whoever made the PCB can publish source and gerbers so that
others can order the same board if they want.
That would be probably the best idea
to start with. I've been staring at
the foto of the pvb for a while, and did notice as you said, only one pin
is being diverted.
10:59 p.m.
New subject: Dual SPI Flash
Pin 1, 'chip select enable' is an inverted? pin. enables and
disables device operation. When chip select is high, the device is
de-selected and the serial data pins are at 'high impedance'.
When
chip select is brought low, the device will be selected and instructions
can be written to and data read from the device.
After power-up, Chip
Select must transition from high to low before a new instruction will be
accepted.
So if I understand all this correctly, the chip can be
connected in parallel with the exception of the Chip Select Enable. A
simple switch to either connect it directly to the board/socket/other
end and toggle it to connect to ground (via 'some' resistor').
I tried
to make a simple schematic in ascii, but failed horribly so i've
attached it to this message as monochrome BMP (only format that I could
quickly think of to be smallest in size). I don't know what value those
resistors need to be (and if the schematic can be even more simplified,
with a single resistor), but I belive this is the schematic used for the
dual-SPI flash 'module'
This seems sensible to me, but my knowledge in
this field is very limited.
On 06-03-12 10:42, Peter Stuge wrote:
Oliver Schinagl wrote:
and compare with the flash chip data sheet.
>> I guess whoever made the PCB can publish
source and gerbers so that
>> others can order the same board if they
want.
>
> That would be probably the best idea to start with. I've
been staring at
> the foto of the pvb for a while, and did notice as
you said, only one pin
is being
diverted.
So check which one
//Peter
2:33 a.m.
New subject: Dual SPI Flash
Oliver Schinagl wrote:
Pin 1, 'chip select enable' is an inverted?
pin. enables and
disables device operation. When chip select is high, the device is
de-selected and the serial data pins are at 'high impedance'.
Correct.
So if I understand all this correctly, the chip can
be
connected in parallel with the exception of the Chip Select Enable.
A simple switch to either connect it directly to the
board/socket/other end and toggle it to connect to ground (via
'some' resistor').
Right. This is what you can see demonstrated in the photos linked to
at the bottom of http://stuge.se/m57sli/ i.e.:
http://stuge.se/m57sli/overview.jpg
http://stuge.se/m57sli/U5.jpg
http://stuge.se/m57sli/U9.jpg
These photos are not from a PC mainboard but the principle hopefully
shows. The connection you describe is indeed how GIGABYTE boards
implement Dual BIOS. What is not shown in my photos are the
resistors, which are mounted onto the GIGABYTE board on pads for that
very purpose.
I tried to make a simple schematic in ascii, but
failed horribly so i've
attached it to this message as monochrome BMP (only format that I could
quickly think of to be smallest in size).
Hint: png
I don't know what value those resistors need to be
(and if the
schematic can be even more simplified, with a single resistor), but
I belive this is the schematic used for the dual-SPI flash 'module'
Not quite, the resistors need to be pull-up and not pull-down. See
e.g. http://stuge.se/flash_switch.png which shows the principle with
resistors, but connects the switch common to GND, instead of to the
mainboard as must be done.
This seems sensible to me, but my knowledge in
this field is very limited.
You're already learning more. Your schematic is correct, but
resistors need to pull up to 3.3V and not down to GND. The values
are, as I wrote earlier, not really critical, just don't go too
much under 1k or you will potentially waste some current.
Also make sure that your switch is the break-before-make type.
//Peter
11:28 p.m.
New subject: Dual SPI Flash
On 06-03-12 19:33, Peter Stuge wrote:
I thought I tried and
came out to 54kb, I redid them in this new version
and it is only 998 bytes! Nice!
Hmm, I made a new 'design' and I put the common
of the switch to the
GND, but you say it should connect to the motherboard? Why is this?
Learn I did,
I'll now try to learn some gEDA and design a basic PCB for
this purpose!
Oliver Schinagl wrote:
After this mail-conversation, those images make perfect sense!
Pin 1, 'chip select enable' is an
inverted? pin. enables and
disables device operation. When chip select is high, the device is
de-selected and the serial data pins are at 'high impedance'.
Correct.
So if I understand all this correctly, the chip
can be
connected in parallel with the exception of the Chip Select Enable.
A simple switch to either connect it directly to the
board/socket/other end and toggle it to connect to ground (via
'some' resistor').
Right. This is what you can see demonstrated in the
photos linked to
at the bottom of http://stuge.se/m57sli/ i.e.:
http://stuge.se/m57sli/overview.jpg
http://stuge.se/m57sli/U5.jpg
http://stuge.se/m57sli/U9.jpg
These photos are not from a PC mainboard but the principle hopefully
shows. The connection you describe is indeed how GIGABYTE boards
implement Dual BIOS. What is not shown in my photos are the
resistors, which are mounted onto the GIGABYTE board on pads for that
very purpose. I tried to make a simple schematic in ascii, but
failed horribly so i've
attached it to this message as monochrome BMP (only format that I could
quickly think of to be smallest in size).
Hint: png I don't know what value those resistors need
to be (and if the
schematic can be even more simplified, with a single resistor), but
I belive this is the schematic used for the dual-SPI flash 'module'
Not
quite, the resistors need to be pull-up and not pull-down. See
e.g. http://stuge.se/flash_switch.png which shows the principle with
resistors, but connects the switch common to GND, instead of to the
mainboard as must be done. This seems sensible to me, but my knowledge in
this field is very limited.
You're already learning more. Your schematic is
correct, but
resistors need to pull up to 3.3V and not down to GND. The values
are, as I wrote earlier, not really critical, just don't go too
much under 1k or you will potentially waste some current.
Also make sure that your switch is the break-before-make type.
//Peter
5:42 a.m.
New subject: Dual SPI Flash
So after a weekend and some playing with gEDA and pcb (learning curve
that was) I drew up a schema [1] from what we talked about earlier.
After spending some hours routing I decided to make a second version
(there is plenty of room on a 5x5 pcb) with the header in the middle,
instead of the edge and thus a 2 design PCB was born [2]. Before I send
this off to the PCB fab and have some boards made, I was hoping what you
guys thought and whether it is sound. I've attached a more or less
'complete' render [3] and one without the silkscreen [4] (probably most
usefull).
(M)any pointers appreciated, this being my first board ever designed :)
[1] dspif_sch.png
[2] dspif_photo.png
[3] dspif.png
[4] dspif_nosilk.png
On 03/07/12 16:28, Oliver Schinagl wrote:
On 06-03-12 19:33, Peter Stuge wrote:
I thought I tried and
came out to 54kb, I redid them in this new
version and it is only 998 bytes! Nice!
Hmm, I made a new 'design' and I put the common
of the switch to the
GND, but you say it should connect to the motherboard? Why is this?
Learn I did,
I'll now try to learn some gEDA and design a basic PCB
for this purpose!
Oliver Schinagl wrote:
After this mail-conversation, those images make perfect sense!
Pin 1, 'chip select enable' is an
inverted? pin. enables and
disables device operation. When chip select is high, the device is
de-selected and the serial data pins are at 'high impedance'.
Correct.
So if I understand all this correctly, the chip
can be
connected in parallel with the exception of the Chip Select Enable.
A simple switch to either connect it directly to the
board/socket/other end and toggle it to connect to ground (via
'some' resistor').
Right. This is what you can see demonstrated in the
photos linked to
at the bottom of http://stuge.se/m57sli/ i.e.:
http://stuge.se/m57sli/overview.jpg
http://stuge.se/m57sli/U5.jpg
http://stuge.se/m57sli/U9.jpg
These photos are not from a PC mainboard but the principle hopefully
shows. The connection you describe is indeed how GIGABYTE boards
implement Dual BIOS. What is not shown in my photos are the
resistors, which are mounted onto the GIGABYTE board on pads for that
very purpose. I tried to make a simple schematic in ascii, but
failed horribly so
i've
attached it to this message as monochrome BMP (only format that I could
quickly think of to be smallest in size).
Hint: png I don't know what value those resistors need
to be (and if the
schematic can be even more simplified, with a single resistor), but
I belive this is the schematic used for the dual-SPI flash 'module'
Not
quite, the resistors need to be pull-up and not pull-down. See
e.g. http://stuge.se/flash_switch.png which shows the principle with
resistors, but connects the switch common to GND, instead of to the
mainboard as must be done. This seems sensible to me, but my knowledge in
this field is very limited.
You're already learning more. Your schematic is
correct, but
resistors need to pull up to 3.3V and not down to GND. The values
are, as I wrote earlier, not really critical, just don't go too
much under 1k or you will potentially waste some current.
Also make sure that your switch is the break-before-make type.
//Peter
8:58 a.m.
New subject: Dual SPI Flash
On 03/21/12 04:42, Peter Stuge wrote:
Oliver Schinagl wrote:
I've attached the .pcb and a more clear version of the schematic. I was
just dabbling with geda's schematic editor and first wired everything
together. It got very messy so decided to just put the net definitions
directly on the pins. This is still the case, but with proper
input/output markers hopefully.
Oliver
I've attached a more or less
'complete' render
Please just send the .pcb so that I can open it. Also,
the schematic
is not very clear.
//Peter
2:54 a.m.
New subject: Dual SPI Flash
I just noticed I've attached the old version of the schematic. Thus a
freshly generated schema.
Oliver
On 03/22/12 01:58, Oliver Schinagl wrote:
On 03/21/12 04:42, Peter Stuge wrote:
Oliver Schinagl wrote:
I've attached the .pcb and a more clear version of the schematic. I
was just dabbling with geda's schematic editor and first wired
everything together. It got very messy so decided to just put the net
definitions directly on the pins. This is still the case, but with
proper input/output markers hopefully.
Oliver
I've attached a more or less
'complete' render
Please just send the .pcb so that I can open it. Also,
the schematic
is not very clear.
//Peter
4:54 a.m.
New subject: Dual SPI Flash
Hi,
the schematic looks good. Sorry I haven't noticed this thread earlier.
I don't know what's your mainboard, but I had some problems with mine
since EFI writes to flash during power up?/down? cycles and doesn't like
hot switched chip during poweroff. Anyways, better be prepared to use
external programmer, like „wiggler clone“ in case of everything fails.
Goodluck,
Tadas
(Mrtadis)
6:11 a.m.
New subject: Dual SPI Flash
On 03/26/12 22:54, Tadas Slotkus wrote:
Hi,
the schematic looks good. Sorry I haven't noticed this thread earlier.
I don't know what's your mainboard, but I had some problems with mine
since EFI writes to flash during power up?/down? cycles and doesn't like
hot switched chip during poweroff. Anyways, better be prepared to use
external programmer, like „wiggler clone“ in case of everything fails.
Goodluck,
Tadas
(Mrtadis)
Thanks, if people here atleast all agree that its sound, I'll send it
off to seeed to have it printed.
From what I understood, SPI is a shared bus, so Chip Select 0/1 should
allow you to switch between various chips/eeproms.
So even if one's motherboard is completly weird, I guess having
chipselect on chip 1 first, boot, then while booted swap to 2, flash new
bios, switch back to 1, shutdown. This should work (I cannot image the
bios/uefi, constantly writing to the eeprom?
Then when powerd down, move your jumpercap/switch back to the newly
flashed eeprom and you should be golden. If the new flash is coreboot,
it shouldn't be a problem anymore, if the new flash is some other
bios/uefi, then take caution when swapping.
But this is what I suspect, I'm sure there's many more people on this
list who actually really know what happens ;)
Oliver
7:08 a.m.
New subject: Dual SPI Flash adapter
Hi list,
Unfortunately I have had little feedback so far. But here's a small update.
I have finally received my SO8 memory modules and those babies are
small. Because of this, I have replaced the SO8M footprint with an SO8W
footprint, making it quite a bit wider, but should be much easier to
manually solder. I tried for an hour to fit a 1008 footprint for the
resistors but there would be hardly any room left for silkscreening.
Also all the smd compontens that I have to salvage seem to be 0603
components anyway. I'm sure people will manage to solder 2 resistors.
I've also saw a screenshot of an Asus motherboard that had the bios chip
right next to a Sata port, in the wrong/different orientation, so I've
added a 3rd design so all 3 possible insertations are possible. (Left,
center and right facing connector).
I've attached the gEDA .pcb file with the 3 orientation, with each
having their individually nets/defs so that the DRC/rat check works.
When sending out the final rev. I'll copy/paste the silk screens from
the left design so they all look identical.
If I get no negative feedback, I'll try to send the boards out for
manufacture next week, so in a month or two I should have about 40 PCB's
and would be happy to send a few out to coreboot dev's, if there's any
interest at all :)
Oliver
7:23 a.m.
New subject: Dual SPI Flash adapter
Oliver Schinagl wrote:
Unfortunately I have had little feedback so far. But
here's a small
update.
Thanks for the update.
I did look at your previous board but needed more time to really look
closely.
I have finally received my SO8 memory modules and
those babies are
small.
Oh it's not so bad. :) Try the 0603 resistors.
Because of this, I have replaced the SO8M footprint
with an SO8W
footprint,
This is actually correct. All SPI flash chips used in PCs are in the
200 mil wide package, not the standard SO8 which is only 150 mil.
I've also saw a screenshot of an Asus motherboard
that had the bios chip
right next to a Sata port, in the wrong/different orientation, so I've
added a 3rd design so all 3 possible insertations are possible. (Left,
center and right facing connector).
Ah, so the plan is that your PCB is plugged into the factory BIOS
socket? That's a nice idea, but as you discovered there are four ways
that the chip can be oriented, so you really have to make four
boards to have a solution that works on every board. :\
I've attached the gEDA .pcb file with the 3
orientation,
Thanks. I'll try to give some more detailed feedback, but one big
no-no that I've seen already is that your silk is covering pads.
Noone will do any cropping for you, so you will indeed get silkscreen
on your pads, which 1) potentially makes the board house unhappy
because it may make a mess in their machines, and 2) makes it
difficult for solder to flow over the pad.
When sending out the final rev. I'll copy/paste
the silk screens
from the left design so they all look identical.
No, please do not make design changes post final review. Another way
to express this is please only send files for review that you believe
that you are finished with. Of course there can be iterations and
that's fine! But don't make further changes after the final
iteration.
//Peter
7:40 a.m.
New subject: Dual SPI Flash adapter
On 04/05/12 01:23, Peter Stuge wrote:
There are 3 SO8 package footprints in PCB, SO8, SO8M and SO8W. None fit
'perfectly'. S08 is way to small to be usefull, SO8M fits 'perfectly'
but makes it extremly hard to solder I recon, since the pad, ends at the
legs. SO8W seems to be a little to wide, the legs end up perfectly on
the inner sides, which might make it not to cover the back 'cavities'
perfectly? But I guess it will have to do.
The PCB's that I used as inspiration actually do fit perfectly :)
http://www.ebay.com/itm/10-pc-SOIC-8-DIP-8-Narrow-PCB-SMD-Adapter-DIP-/4002…
Yes, the plan was to have
the PCB go into the motherboard, and the
original bios piggy bags ontop! The
Well, 4 orientations, but I think 1 can be used for 2 orientations. It
all depends on what is blocking your board however.
I hope it's quite unlikly that a bios is constrained on 3 sides, but as
always possible. If I get bored later this week, I may end up making the
missing 4th design then, where the socket sits 'sideways'. Should be
considerably easier to route then the ones I have now ...
Hmm, I assumed silk screening is applied
last, as I have seen
soldermasks and silkscreening covering via's. The only thing I cover IS
via's ... because of that assumption.
I should have clarified this yes, I would of course have posted the
final version that would have been sent off to the board house. But that
version will fail DRC checking :(
Oliver Schinagl wrote:
That would be grand!
Unfortunately I have had little feedback so far.
But here's a small
update.
Thanks for the update.
I did look at your previous board but needed more time to really look
closely. I have finally received my SO8 memory modules and
those babies are
small.
Oh it's not so bad. :) Try the 0603 resistors.
Because of this, I have replaced the SO8M
footprint with an SO8W
footprint,
This is actually correct. All SPI flash chips used in PCs are in the
200 mil wide package, not the standard SO8 which is only 150 mil. I've also saw a screenshot of an Asus
motherboard that had the bios chip
right next to a Sata port, in the wrong/different orientation, so I've
added a 3rd design so all 3 possible insertations are possible. (Left,
center and right facing connector).
Ah, so the plan is that your PCB is plugged into the factory BIOS
socket? That's a nice idea, but as you discovered there are four ways
that the chip can be oriented, so you really have to make four
boards to have a solution that works on every board. :\ I've attached the gEDA .pcb file with the 3
orientation,
Thanks. I'll try to give some more detailed feedback, but one big
no-no that I've seen already is that your silk is covering pads.
Noone will do any cropping for you, so you will indeed get silkscreen
on your pads, which 1) potentially makes the board house unhappy
because it may make a mess in their machines, and 2) makes it
difficult for solder to flow over the pad. When sending out the final rev. I'll
copy/paste the silk screens
from the left design so they all look identical.
No, please do not make design changes post final review. Another way
to express this is please only send files for review that you believe
that you are finished with. Of course there can be iterations and
that's fine! But don't make further changes after the final
iteration.
//Peter
7:53 a.m.
New subject: Dual SPI Flash adapter
Oliver Schinagl wrote:
No. See attached file, or http://stuge.se/4.png if it gets stripped
from the list.
//Peter
There are 3 SO8 package footprints in PCB, SO8, SO8M
and SO8W. None fit
'perfectly'.
I'll see if I can send you a footprint I've used.
Thanks.
I'll try to give some more detailed feedback, but one big
no-no that I've seen already is that your silk is covering pads.
Noone will do any cropping for you, so you will indeed get silkscreen
on your pads, which 1) potentially makes the board house unhappy
because it may make a mess in their machines, and 2) makes it
difficult for solder to flow over the pad.
Hmm, I assumed silk screening is applied last, as I have seen
soldermasks and silkscreening covering via's. The only thing I
cover IS via's ... 
2975
days inactive
3004
days old
16 comments
4 participants
participants (4)
-
Oliver Schinagl -
Oliver Schinagl -
Peter Stuge -
Tadas Slotkus