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Hewlett Packard NS-2 processorsIntroduction: 1989The last NMOS-based PA-RISC processor was the NS-2, a tweaked follow-on to the NS-1 with increased pipeline stages (from three to five), new TLB and cache controllers and significantly larger caches (1MB) and TLBs (16K). The NS-2 design was simplified over its NS-1 predecessor. The processor is contained on one processor circuit board and integrates the CPU as a single NMOS-III chip, with seven other VLSI (NMOS-III) chips on its side: SIU (System Interface Unit), two CCUs (Cache Controller Units, split into instruction and data - ICCU and DCCU), TCU (TLB Controller Unit), FPC (Floating Point Controller, speaks to the FP chips) and two third-party floating point (FP) chips (ADD, MULTI). The bus structure connecting these chips was updated (and simplified), with the CPU having private connections to the cache and TLB controllers (for which the NS-1 CPU had to use the shared cache bus).
Source: www.openpa.net |
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