Feature Extension Retrofits#

This page documents helpful PCB retrofits that add new functionalities to existing carrier boards. All retrofits that aim at fixing bugs are documented in Known issues and remedies.

Adapter card identification retrofit#

The retrofit adds address pins to the A and D connectors between the UltraZohm carrier board and its various A and D adapter cards. By doing so, the EEPROMs on current and future adapter cards become reachable, which enables the Platform Framework (running on the PS CPUs) to fetch the card identification (model, revision and serial) and hand it over to the user. The user may rely on this too, e.g., select/apply any card-specific calibration datasets as required during system initialization, for instance, on ADC or DAC cards, to compensate for part-based offsets or other analog differences. The retrofit requires soldering multiple wires on the carrier board.

Note

This retrofit only applies to UltraZohm with a carrier board of Rev04. Carrier boards with Revision 3 and earlier can not be retrofitted to add the adapter card identification feature. The systems with the serial number (see the back of the system) 002-001-0400-0002 to 001-001-0401-0016 can be upgraded. Systems with the serial number 00x-001-0401-0017 and higher (e.g., -0030) do not require the upgrade since the feature is added by default.

Prerequisites and preparation#

Required tools:

  • Screwdrivers

  • Soldering iron

  • Tin solder

  • Thin enameled (copper) wire (magnet wire)

Soldering should take less than ten minutes; the mechanics depend on your specific hardware setup since the carrier board has to be disassembled from the chassis.

Warning

Given the sensitive nature of the electronics on the carrier board, please deploy the usual ESD prevention methods during disassembly, soldering, and reassembly.

Step-by-step PCB instructions#

This retrofit aims to add slot-specific voltage levels to two/three predefined connector pins (A and D slots, respectively) for the (up to) eight adapter cards that can be connected to the UltraZohm carrier. Due to the design of this feature, selected connector pins have to be connected to only ground (GND), not to any other signal. Given that all slots on the carrier are “surrounded” by GND, this greatly simplifies the retrofit (as newly added wires can be kept short and do not have to reach any supply rail).

Important aspects:

  • For A slots, between one and two connector pins (per slot) shall be connected to GND

  • For D slots, between zero and two connector pins (per slot) shall be connected to GND

  • For both types of slots, the connector pins in question are easily accessed using test pads close to the connector

  • GND is readily available using a large plane surrounding all connectors and “made accessible” by carefully removing the solder mask layer on top

  • Connections between the individual test pads and the – potentially shared – “GND spot” shall be made using enameled wire

The following image shows the individual test pads that have to be connected to GND:

../../_images/adretro2d.png

They are

  • TP46A and TP56A at slot A1,

  • TP56B at slot A2 (not labelled on the overlay silkscreen – orange label above added for clarity),

  • TP46C at slot A3,

  • TP58A at slot D1,

  • TP57B and TP67B at slot D2,

  • TP67C at slot D3,

  • TP57D at slot D4, and

  • (none) at slot D5.

The following 3D rendering shows the affected slots and test pads (NB: slot D5 thus not shown here):

../../_images/adretro3d.png

To connect the above pads to GND:

  • Select a suitable “GND spot” close to the pad(s), i.e.,

    • one left of A1, A2 and A3 each,

    • one between D1 and D2, and

    • one left of D3 and D4 each;

  • carefully remove the solder mask layer on top;

  • apply soldering iron and (tin) solder to blank copper until some solder has been deposited;

  • pre-solder the test pad(s) affected on the particular slot;

  • solder some enameled wire to the pre-soldered test pad(s); and

  • solder the enameled wire(s) to the GND point created before.

The soldering step-by-step photos below exemplify the above steps by means of the shared GND point between slots D1 and D2, whilst Retrofitted Carrier Card shows the final result.

Table 68 soldering step-by-step photos#

Remove GND solder mask

Pre-solder GND point

Pre-solder test pad(s)

Add enameled wire(s)

Connect wire(s) to GND
../../_images/adretrostep1.jpg ../../_images/adretrostep2.jpg ../../_images/adretrostep3.jpg ../../_images/adretrostep4.jpg ../../_images/adretrostep5.jpg
../../_images/adretroboard.jpg

Fig. 80 Retrofitted Carrier Card#

Please refer to Platform Framework for a description of the software API that helps to retrieve the per-card identification data on the APU.

Further reading#

Please refer to the following references for more details.