1. B. Hirosky 12/14/00 FPGA + FIFO replaces: DMA P/IO buffers TSI device Keep ECL drivers BUY THIS! Same Basic Concept as L2Alpha, but with simplified implementation ‘L2ßeta’ CPU

2. B. Hirosky 12/14/00 ‘L2ßeta’ Implementation Hardware Components 6U VME SBC w/ integrated UII 9U adapter card w/ custom i/o devices PCI (PMC) to adapter bridge card Draft technical note at: www-d0.fnal.gov/~hirosky/l2b

3. B. Hirosky 12/14/00 Practical goals Minimal engineering Maximum use of manufactured components (hardware/firmware) Hardware compatibility w/ present system MBus/VME compliance Software (source code) compatibility w/ present system Device driver APIs Short development time Support/flush out L2 if hardware set not complete Long term solution to L2 support freedom from parts obsolescence for repair/spares clear upgrade path to modern/powerful CPUs

4. B. Hirosky 12/14/00 Hardware Engineering Components Interface Card: sits on PMC needs to support PCI interface on front end and local interface on back end (preferably supports 33 and 66MHz buses) Adapter Card: contains FIFO’s ECL and Mbus drivers, and control FPGA

5. B. Hirosky 12/14/00 Software/Firmware Engineering Components SBC: Linux interrupt handler Linux memory mapper Device driver code Interface Card: PCI interface module, local interface firmware Adapter Card: FPGA Firmware, controls MBus i/o, DMA

6. B. Hirosky 12/14/00 Block prototype for software and firmware components

7. B. Hirosky 12/14/00 Source code compatibility - needs new PCI base classes (PCIDEV, PCICFG, CIA) the UII driver should be transparent - need new drivers for replace MB devices and TSI - easy - “minor” linux tweeks --->> result = source code compatible boards! Can select hotter CPU boards for Global worker or cooler boards for Administrators

8. B. Hirosky 12/14/00 Many vendors for SBC cards, most VME SBCs have UIIB’s on board. Small companies w/ off the shelf boards + custom options Medium companies like SBS w/ off the shelf boards Giant companies like Raytheon too! Medium and High End CPU’s available now vs. our alpha: SPECint95 SPECfp95 SBC PCI Cost Alpha 500 MHz 15.4 21.1 64/33 ~$5K (complete) PIII 800MHZ 38.4 28.4 32/33 ~$4K (SBS) (PIII 1GHz now available) POWERPC 750 22.4 13.3 32/33 (550MHz) 7400 21.4 20.4 32/33 SPARC II 18 22 64/33 ~$3.5K (Momentum) SPARC III 35+ 60+ ? N/A (Faster SPARCIIs expected)

9. B. Hirosky 12/14/00 Issues Can we live w/ a 33MHz 32-bit bus? ~(125MB/s) Probably, if we can do full speed to RAM. This is about the same as we have now! If so, could we easily upgrade to a 66MHz 32bit bus? (depends on PCI interface hardware – ie YES if ALTERA megacore or similar) Can we instead use AGP for broadcast? (>500MB/s) (Commercial prototype cards are available) Compilers for SPARC under Linux? “Experimental g++”, Linux->SPARC cross compiler,... (SOLARIS out of the question? Compilers available=KAI, SUN) Alas, KAI supports INTEL/ALPHA Linux, not SPARC Linux Linux kernal mods - expect easier time in Pentium..