Projects issueshttps://ohwr.org/groups/project/-/issues2022-01-25T07:48:44Zhttps://ohwr.org/project/svec/issues/60V3 - Replace DDR3 memory by DDR3 SO-DIMM module2022-01-25T07:48:44ZErik van der BijV3 - Replace DDR3 memory by DDR3 SO-DIMM module**Background**
- With the new 1/2GSPS 8-bit ADC mezzanines, the memory bandwidth of the two 16-bit DDR chips used currently on the SVEC carrier [1] is insufficient.
- Xilinx's DDR3 controller performance is quite low compared to alternatives.
- DDR3 chips are getting difficult to obtain.
**Tasks**
- Remove the two DDR3 chips from the SVEC.
- Connect a DDR3 SO-DIMM module socket instead with 64-bit data path width (some pin swapping/reassignment might be needed).
- Evaluate the performance of the LiteDRAM controller with AXI4-full host interface, port it to SVEC AFPGA and validate with the SO-DIMM module [1].
- Provide proof-of-concept VHDL/Verilog code.
[1] https://github.com/enjoy-digital/litedramEDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/59V3 - mini displayPort connector obsolete (J5, J9)2019-06-13T13:47:39ZErik van der BijV3 - mini displayPort connector obsolete (J5, J9)The mini displayPort connector (J5 and J9) is obsolete and the last production in 2018 had these removed (and the front-panel was redone without holes in these locations).
See if any alternative can be found for the GENESIS MDPR-2020-BK63U1F, which likely needs another footprint.EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/1V3 - D1 Shottky Diode Vishay 50WQ06FNPbF EOL, obsolete2022-12-05T15:07:08ZErik van der BijV3 - D1 Shottky Diode Vishay 50WQ06FNPbF EOL, obsoleteD1 1 60V 5.5A Schottky Rectifier 50WQ06FNPbF VISHAY SEMICONDUCTOR
50WQ06FNPbF is at EOL.
JanzTec recommends to replace by Vishay 50WQ06FN-M3 that has all the
same parameters. This will be used in the 2018 production run.EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/2V3 - PCB and schematics wrong for use of optional USB - FTDI chip2022-12-05T15:07:08ZErik van der BijV3 - PCB and schematics wrong for use of optional USB - FTDI chipWhen the option for the USB - FTDI chip (FT2232HL) needs to be used, it
will not work. There is a problem that appears when the optional
components for this will be mounted.
See the attached image. Page 13 of the schematics shows that the line
connected on the left of R248 is called USB\_TMS (like the one connected
to R243). The line to R248 should be USB\_TDI.
Schematics at:
https://edms.cern.ch/file/1421529/1/EDA-02530-V3-0_sch.pdf (page 13)
*Problem reported by JanzTec (16/5/18)*
### Files
* [USB_TMSx2_bottom_one_wrong.png](/uploads/f4219c9bc8b7cf31cf94b81dfa26da77/USB_TMSx2_bottom_one_wrong.png)EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/3V3 - SFP cage type is obsolete, EOL2022-12-05T15:07:07ZErik van der BijV3 - SFP cage type is obsolete, EOLThe two-piece SFP Cage from Tyco Electronics
([6367034-1](http://www.te.com/usa-en/search.html?q=6367034-1) and
[6367035-1](http://www.te.com/usa-en/search.html?q=6367035-1)) is at
End-of-Life (EOL).
The supplier suggests the use of the one-piece solution
[2227303-3](http://www.te.com/usa-en/product-2227303-3.html).
This solution will be used (with agreement from CERN) for new
productions by JanzTec from January 2018 on.
*Reported by JanzTec on 22/1/18.*EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/9V3 - debug LEDs ROHM SML-311UTT86K not available2022-12-05T15:07:08ZErik van der BijV3 - debug LEDs ROHM SML-311UTT86K not availableThe ten LEDs on the board, used for debugging (SML-311UTT86K) is not
available anymore.
The SML-311UTT86 would be the same LED but they have a difference in
brightness:
with K: 4.0 – 6.3 mcd at 2mA
without K: 0.9 – 2.5 mcd at 2mA
Suggest to replace
SML-311UTT86K by
SML-311UTT86
Problem and solution from Janz. Agreed with Erik.
LED type will be different on productions from August 2017 on.EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/12V3 - schematics: VMEPX_SERA and SERB shown, but not used2022-12-05T15:07:08ZErik van der BijV3 - schematics: VMEPX_SERA and SERB shown, but not usedThe VMEPX\_SERA and SERB on VME P1, pins B21 and B22 are shown on pages
18 and 19 of the schematics. But they are actually not used (they are
only connected on the P1 connector).
These are the serial I2C lines that are for example on an ELMA VME
crate. They cannot be used on the SVEC as they are not connected.
- Remove from schematics to remove confusion *or*
- Add a buffer and connect to Xilinx (cf. CONV-TTL-BLO) so that they
can used for stand-alone systems not requiring a processor with VME
busEDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/13V3 - Resistor settings show V2, not V32019-06-13T13:47:38ZErik van der BijV3 - Resistor settings show V2, not V3There are some resistors that should show which version of PCB is
used.
Unfortunately the settings on the V3 are the same as on the V2.
Not a problem as they are fully compatible.
Make sure new versions have the correct setting.EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/21V2 - Pullback on top and bottom layers is too small2019-06-13T13:47:39ZProjectsV2 - Pullback on top and bottom layers is too smallPullback on top and bottom layers (for ESD polygons) is 0.192mm and
should be at least 0.2mm
### Files
* [Screenshot-rdesktop_-_rdseda19.cern.ch-1.png](/uploads/d51211a3c99fa59cbb8511e857d525db/Screenshot-rdesktop_-_rdseda19.cern.ch-1.png)EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowskihttps://ohwr.org/project/svec/issues/29V1 - Uneven track width2019-06-13T13:47:39ZProjectsV1 - Uneven track widthSome tracks for similar signals (e.g. VME signals) have uneven track
width.
### Files
* [SVEC_track_width.jpg](/uploads/43d56f67f8170fb23bdfe5f4ee683007/SVEC_track_width.jpg)EDA-02530-V4-0Tomasz WlostowskiTomasz Wlostowski