Frequently Asked Questions

Hardware

Q: does the board comply to CE regulations (EMC)?

A: Yes it does. In June 2012 extensive EMC tests have been performed on the SPEC with a digital I/O (FMCDIO5chTTLa) card. These tests have been made by AT4 wireless, a testing laboratory accredited by the Spanish National Accreditation Body (ENAC -Entidad Nacional de Acreditación) to perform the tests indicated in the Certificate No. 51/LE 203.
The test report is publicly available and shows that the card has passed the most restrictive EMC tests of each class (domestic and industrial) successfully:

EM Radiated Emission: Class B (Domestic) EN 55022 (2006) / A1 (2007)
EM Immunity (Industrial): EN 61000-4-3 (2006) / A1 (2008) / A2 (2010), EN 61000-4-4 (2004) / A1 (2010) / Corr (2010), EN 61000-4-6 (2009), EN 61000-4-2 (2009), EN 61000-4-8 (2010).

Q: What are the differences between V1-0, V1-1 and V2-0?

A: V1-0 and V1-1 have different output buffers (SN74LS125 vs SN74LVT125) caused by a mistake in the PCB library and resulting in poor output pulse rise time and inability to drive 50 ohm loads in V1-0. V2-0 has improved I/O protection circuit which works also when the card is not powered. V1-0/V1-1 PCB designs are identical, in order to identify the version, check the types of buffers soldered (IC2, IC5).

Q: My card seems to be missing IPMI FRU information in the EEPROM. Can it be fixed?

A: Many cards miss that information, as it was not supported by the DIO PTS (Production Test System). A temporary procedure to fix this issue goes as follows:

- Make sure you're using the latest master of the SVEC/SPEC drivers.

- Download the eeprom-dio.bin file from the Files section.

- Load the SPEC/SVEC driver and the golden bitstream
- Program the EEPROM with the command (as root, replace XXXX with the ID of the mezzanine):

cat eeprom-dio.bin > /sys/bus/fmc/devices/fmc-XXXX/eeprom

- Reload the driver. Now it should enumerate the card correctly:

svec svec.0: mezzanine 0
      Manufacturer: CERN
      Product name: FmcDIO5chTTLa

Q: What is the input level if I do not program the card?

A: The default input level after power-on will be 1.65V, the power-up output level of the DAC. See the datasheet https://www.ti.com/lit/ds/symlink/dac5578.pdf, page 38 and in this design RSTSEL is connected to AVDD). Also the Note on the dio hardware design describes this in the last section.

Tomasz Wlostowski, Erik van der Bij - 25 August 2020

Faq