Wednesday, July 9, Notes Present: Ed Barsotti, Mark Bowden, Aesook Byon-Wagner, Bob DeMaat Jim Patrick, Keith Schuh, Ted Zmuda Mark Bowden and Ted Zmuda met with the PCBCP to review the VRB (VME Readout Buffer) and the VRB Fanout being developed by the Computing Division. The panel was provided with the following documentation: Document describing the functionality and operation of the VRB and VRB Fanout Schematic diagram of the VRB Schematic diagram of the VRB Fanout Mark and Ted brought brought prototypes of the VRB and VRB Fanout to the review. These are both 9-U x 400mm cards. The VRB has a choice of either G-Link or TAXI for receiving data on the transition module. There is an Industry Pack connector on the front for either ethernet or 1394 operation. The VRB is a VMEbus slave and it uses D16 transfers only. It utilizes a Motorola 68030 to set up the board and program the Field Programmable Gate Arrays. Power is provided via J1 and J0. The board idles at approximately 15 watts and is expected to dissipate no more than 40 watts during operation. The VRB is fused with two 5-amp fuses and one transorb. It uses +5 and +/-12 volts. The +/-12 will be used for the Industry Pack connector only. ETL logic is used for the VMEbus interface. A new G-Link board has been designed which will run off of +5 volts so -5.2 volts will no longer be needed. The next version of the VRB is expected in the next few days. The VRB Fanout is fused. It is also fused for the power terminators on the J3 backplane. Keith points out that the space between the prototype stiffener and the outer contacts on the 160-pin connector might cause problems with capacitance or shorts if dirt accumulates here. Ted thought that anodizing the stiffener may be an appropriate measure to take since this coating is an insulator. Ted notes that the majority of the I/O cabling will be on the front of the subrack. Keith feels that a routing channel in the rack will be called for. There will be 6 VRB's to 1 Fanout in a subrack. 6 VRB's will be used by SVX. The current test stand uses the General System Test Module (GSTM) with a G-Link adapter. The system uses an IBM compatible PC. The VRB operates at 26 MHz internally. It combines pairs of 8-bit data and transfers this data on 16-bit buses. The VRB will be used for CDF SVX, D0 SVX and CDF Calorimeter. The CDF version uses VME A32 addressing. The D0 version uses A24 addressing. PREP will provide the first level of effort for long term test and repair of the VRB. The large, fine-pitch chips such as the Altera parts may require additional tools to allow replacement should failures occur. Spares can be common between CDF and D0 if D0 chooses to populate their VRB's with 10 channels rather than 8 which is the number required in D0's application. Software is currently being developed with a Macintosh 68000 compiler. Module ID's need to be assigned within CDF. The methods for reading out the module ID's need to be evaluated and standardized where possible. If you find inaccuracies (or omissions) you would like to have corrected, please send comments to Bob DeMaat. demaat@fnal.gov fnald::demaat