diff options
| -rw-r--r-- | docs/install/bbb_setup.html | 26 | ||||
| -rw-r--r-- | docs/tasks.html | 40 |
2 files changed, 26 insertions, 40 deletions
diff --git a/docs/install/bbb_setup.html b/docs/install/bbb_setup.html index 0c512512..d1a4e3d8 100644 --- a/docs/install/bbb_setup.html +++ b/docs/install/bbb_setup.html @@ -297,6 +297,21 @@ Note: flashrom can never write if the flash chip isn't found automatically. 18 - - 3.3V PSU RED 22 - - NC - this is pin 1 on the flash chip <i>This is how you will connect. Numbers refer to pin numbers on the BBB, on the plugs near the DC jack.</i> + +You may also need to connect pins 1 and 9 (tie to 3.3V supply). These are HOLD# and WP#. +On some systems they are held high, if the flash chip is attached to the board. +If you're flashing a chip that isn't connected to a board, you'll almost certainly +have to connect them. + +SOIC16 pinout (more info available online, or in the datasheet for your flash chip): +HOLD 1-16 SCK +VDD 2-15 MOSI +N/C 3-14 N/C +N/C 4-13 N/C +N/C 5-12 N/C +N/C 6-11 N/C +SS 7-10 GND +MISO 8-9 WP </pre> <p> The following shows how to connect clip to the BBB (on the P9 header), for SOIC-8 (clip: Pomona 5250): @@ -307,6 +322,17 @@ Note: flashrom can never write if the flash chip isn't found automatically. NC - - 21 3.3V PSU RED - - 17 - this is pin 1 on the flash chip <i>This is how you will connect. Numbers refer to pin numbers on the BBB, on the plugs near the DC jack.</i> + +You may also need to connect pins 3 and 7 (tie to 3.3V supply). These are HOLD# and WP#. +On some systems they are held high, if the flash chip is attached to the board. +If you're flashing a chip that isn't connected to a board, you'll almost certainly +have to connect them. + +SOIC8 pinout (more info available online, or in the datasheet for your flash chip): +SS 1-8 VDD +MISO 2-7 HOLD +WP 3-6 SCK +GND 4-5 MOSI </pre> <p> <b>NC = no connection</b> diff --git a/docs/tasks.html b/docs/tasks.html index 5ce2bc95..f59a5855 100644 --- a/docs/tasks.html +++ b/docs/tasks.html @@ -253,46 +253,6 @@ Get them for the following remaining boards: X60, T60, macbook21, R400 </li> <li> - Apparently, leaving HOLD and WP pins floating (unconnected) isn't a good idea. - Information online says that this needs to be connected along with 3.3V - look into this. - (it is specific to each flash chip, so read the datasheets). - <ul> - <li> - eg http://flashrom.org/FT2232SPI_Programmer - - " The WP# and HOLD# pins should be tied to VCC! If you leave them unconnected you'll likely experience strange issues." - </li> - <li> - <pehjota> stefanct: We've never had any "strange issues" with leaving WP# and HOLD# - unconnected on the Macronix and Atmel SOIC-8 and SOIC-16 flash chips on the X200. - IIRC, the datasheets don't say how those pins are wired internally or whether they can - be left unconnected. But I tested their voltages while flashing, and they float high - on their own, so they seem to support it fine. - </li> - <li> - <pehjota> fchmmr: You would connect the WP# and HOLD# pins to 3.3 V (on an ATX PSU you'd - hook up more cables to the other orange pins, with your PSU I guess you'd wrap more wires - around the 3.3-V screw), just like you do VCC. But as I said above, it doesn't seem to - be necessary (WP# and HOLD# seem to be held high already).<br/> - <pehjota> I got a solid ~3.3 V (i.e. pulled high, not floating between high and low) - from WP# and HOLD# with just VCC, GND, MOSI, MISO, CS#, and SCLK connected. Plus, we haven't - had any write protection issues as I'd expect from floating WP# and HOLD#, AFAIK.<br/> - <pehjota> fchmmr: These pins do nothing if they're held high. The "#" (not) means they cause different behavior when held low. - </li> - <li> - <stefanct> fchmmr: pehjota: it may not be a problem if the chip is soldered to the x200, but it surely is when it isnt. - </li> - <li> - <stefanct> yes... - <stefanct> a small note noting that would be appreciated because there are enough people out there already that ignore those pins and get stuck - >pehjota> stefanct: You mean a note in the libreboot documentation explaining why we don't have to connect HOLD# and WP# to anything and how they would have to be tied to VCC on a chip not soldered to a board? - <Kamilion> How about a more useful note that explains the whole discussion you two had succinctly? - <Kamilion> Not everyone is going to be an EE to know about the # indicating the pin should be pulled low to be active. - <Kamilion> reminds me, I need to pull out my pomona and try to fix some intel NIC roms - <stefanct> pehjota: yes - </li> - </ul> - </li> - <li> Adapt the notes at <a href="install/bbb_setup.html#stability">install/bbb_setup.html#stability</a> into a full guide. </li> |