DIP8 flash programming for development

[Pedro Erencia]

Hi,

I'm thinking about porting coreboot to a FM2A88X Extreme4+ board. This
board has a DIP8 flash with a socket and I wondered what would be the best
way to do an efficient development cycle. Ideally, I suppose that the best
option would be to use a clip test and a CH341A, but all the clips that I
found are SOIC/SOP. Should I buy a SOIC clip and an adapter from SOIC to
DIP? I've seen those adapters, but I'm not sure if they will fit well in
the mobo DIP8 socket.

Aside from the mechanical question, I'd appreciate any advice about the
safety of externally programming the board. I don't have the schematics and
I wonder if there could be any risk of damaging the board.

Cheers.

[Nico Huber]

Hi Pedro,

On 27.11.21 00:02, Pedro Erencia wrote:
> I'm thinking about porting coreboot to a FM2A88X Extreme4+ board. This
> board has a DIP8 flash with a socket and I wondered what would be the best
> way to do an efficient development cycle. Ideally, I suppose that the best
> option would be to use a clip test and a CH341A, but all the clips that I

the CH341A is a rather slow programmer and the most popular version uses
5V i/o while you most likely need 3.3V. I would rather use something
FT*232H based (the H is important, it's high-speed and speaks SPI) or
maybe a stm32 "blue-pill" with firmware from [1].
> found are SOIC/SOP. Should I buy a SOIC clip and an adapter from SOIC to
> DIP? I've seen those adapters, but I'm not sure if they will fit well in
> the mobo DIP8 socket.

Not sure what adapter you are talking about. Clips are not good for
development anyway; they are most useful if you want to program a
device just once and then go on with the next device. What I would
do (but not sure if I'd recommend that): Solder wires somewhere at
to the tops of the DIP8 legs. So you could still plug it into the
socket. Or maybe I would try to squeeze some stranded wire along with
the chip into the socket. Anyway, I would consider something more
professional, see below.
> Aside from the mechanical question, I'd appreciate any advice about the
> safety of externally programming the board. I don't have the schematics and
> I wonder if there could be any risk of damaging the board.

To be safe, there should be some sort of isolation between the mainboard
components and the programmer. If you don't have schematics of the main-
board, you can't tell if there is any on the board already, and I would
suggest a "qspimux" [2]. Usually a connector for it is soldered to the
board, but it should be possible to use a DIP8 socket too.

Nico

[1] https://github.com/dword1511/stm32-vserprog
[2] https://github.com/felixheld/qspimux

[Ken Pillay]

you could end up "bricking" the motherboard.
> On Fri, Nov 26, 2021 at 3:02 PM Pedro Erencia <[e-mail]> wrote:
> Hi,
>
> I'm thinking about porting coreboot to a FM2A88X Extreme4+ board. This
> board has a DIP8 flash with a socket and I wondered what would be the best
> way to do an efficient development cycle. Ideally, I suppose that the best
> option would be to use a clip test and a CH341A, but all the clips that I
> found are SOIC/SOP. Should I buy a SOIC clip and an adapter from SOIC to
> DIP? I've seen those adapters, but I'm not sure if they will fit well in
> the mobo DIP8 socket.
>
> Aside from the mechanical question, I'd appreciate any advice about the
> safety of externally programming the board. I don't have the schematics and
> I wonder if there could be any risk of damaging the board.
>
> Cheers.
>
> _______________________________________________
> coreboot mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

[Angel Pons]

Hi Pedro,

On Fri, Nov 26, 2021 at 11:02 PM Pedro Erencia <[e-mail]> wrote:
> Hi,
>
> I'm thinking about porting coreboot to a FM2A88X Extreme4+ board. This board has a DIP8 flash with a socket and I wondered what would be the best way to do an efficient development cycle. Ideally, I suppose that the best option would be to use a clip test and a CH341A, but all the clips that I found are SOIC/SOP. Should I buy a SOIC clip and an adapter from SOIC to DIP? I've seen those adapters, but I'm not sure if they will fit well in the mobo DIP8 socket.

I wouldn't recommend a CH341A for the same reasons Nico explained, and
would suggest the same alternatives.

I've done a lot of development on the Asrock B85M Pro4 (a completely
different board, but also has a socketed DIP8 flash chip) and, for me,
the most efficient development cycle is to use a flash emulator like
the Dediprog EM100. However, flash emulators aren't cheap. Before I
had the EM100, I simply moved the flash chip back and forth by hand,
from the mainboard to a breadboard wired to a CJMCU FT2232HL mini
module (external programmer) and viceversa. I added another DIP8
socket between the flash chip and the mainboard's socket, so that I
could easily and quickly remove and replace the flash chip.
> Aside from the mechanical question, I'd appreciate any advice about the safety of externally programming the board. I don't have the schematics and I wonder if there could be any risk of damaging the board.

If you remove the flash chip from the mainboard to reflash it, it's
practically impossible to damage the board.
> Cheers.
>
> _______________________________________________
> coreboot mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

Best regards,
Angel

[Ivan Ivanov]

Hi friends, if you are serious about CH341A - get a version with a
green PCB board, it's more likely to give you 3.3V (instead of the
erroneous 5V which the bugged version of black CH341A could be
giving). And just in case, verify the output pins with a multimeter,
to see it's really a 3.3V...
Also, why do you need a test clip at all? If your board has DIP8 flash
chip, most likely it's inside a socket - and possible to remove using
a PLCC / DIP8 remover, to directly plug into the "flashrom-supported"
programmer like CH341A.
> flash emulator like the Dediprog EM100
> That's very interesting, never heard of it :) Although they are quite expensive

сб, 27 нояб. 2021 г. в 21:39, Angel Pons <[e-mail]>:
> Hi Pedro,
>
> On Fri, Nov 26, 2021 at 11:02 PM Pedro Erencia <[e-mail]> wrote:
> > Hi,
> >
> > I'm thinking about porting coreboot to a FM2A88X Extreme4+ board. This board has a DIP8 flash with a socket and I wondered what would be the best way to do an efficient development cycle. Ideally, I suppose that the best option would be to use a clip test and a CH341A, but all the clips that I found are SOIC/SOP. Should I buy a SOIC clip and an adapter from SOIC to DIP? I've seen those adapters, but I'm not sure if they will fit well in the mobo DIP8 socket.
>
> I wouldn't recommend a CH341A for the same reasons Nico explained, and
> would suggest the same alternatives.
>
> I've done a lot of development on the Asrock B85M Pro4 (a completely
> different board, but also has a socketed DIP8 flash chip) and, for me,
> the most efficient development cycle is to use a flash emulator like
> the Dediprog EM100. However, flash emulators aren't cheap. Before I
> had the EM100, I simply moved the flash chip back and forth by hand,
> from the mainboard to a breadboard wired to a CJMCU FT2232HL mini
> module (external programmer) and viceversa. I added another DIP8
> socket between the flash chip and the mainboard's socket, so that I
> could easily and quickly remove and replace the flash chip.
> > Aside from the mechanical question, I'd appreciate any advice about the safety of externally programming the board. I don't have the schematics and I wonder if there could be any risk of damaging the board.
>
> If you remove the flash chip from the mainboard to reflash it, it's
> practically impossible to damage the board.
> > Cheers.
> >
> > _______________________________________________
> > coreboot mailing list -- [e-mail]
> > To unsubscribe send an email to [e-mail]
>
> Best regards,
> Angel
> _______________________________________________
> coreboot mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

[David Hendricks]

On Sat, Nov 27, 2021 at 10:39 AM Angel Pons <[e-mail]> wrote:
> Before I
> had the EM100, I simply moved the flash chip back and forth by hand,
> from the mainboard to a breadboard wired to a CJMCU FT2232HL mini
> module (external programmer) and viceversa. I added another DIP8
> socket between the flash chip and the mainboard's socket, so that I
> could easily and quickly remove and replace the flash chip.

I've done this as well. A couple parts recommendations to make this easier:
- High quality DIP8 sockets with rounded legs such as
https://www.digikey.com/short/q0522m77. Those tend to be much easier to
insert and remove into a motherboard's socket than flash chips which have
flimsy legs and will help prevent damage to the mainboard socket when
removing and inserting the chip repeatedly. And if you need to solder
something, it's better to do it on one of these sockets than soldering to
the motherboard or the chip itself.

- If you have your programmer connected to a breadboard, keep a ZIF DIP
test socket like this mounted in place to make inserting and removing the
chip quick and easy: https://www.aliexpress.com/item/32708487337.html.