Sun Microsystems 220R - Manual (Page 272)

4 PCI-to EBus/Ethernet controller (PCIO)
4 UPA-to-PCI bridge (U2P)
4 Frame buffer controller (FBC)
4 Reset, interrupt, scan, and clock (RISC)
C.1.12.1 XB9+
The XB9+ ASIC is a buffered memory crossbar device that acts as the bridge between
the six system unit buses. The six system unit buses include two processor buses, a
memory data bus, a graphics bus, and two I/O buses. The XB9+ ASIC provides the
following:
4 Six-port crossbar
4 Decoupled memory port; loading and unloading of memory data can take place in
parallel with other operations
4 Burst transfers operate on a doubleword of data per slice
4 A total of eight two-entry first-in-first-out (FIFO) devices for read data storage
4 Power-up safe buses (tristated)
C.1.12.2 QSC
The QSC ASIC provides system control. It controls the UPA interconnect between the
major system unit components and main memory. The QSC ASIC provides the
following:
4 Interconnect packet receive
4 Memory arbiter
4 Non-cached arbiter
4 Memory controller
4 Snoop interface
4 Coherence controller
4 S_register dispatcher
4 Internet packet send
4 Datapatch scheduler
4 EBus interface
C.1.12.3 PCIO
The PCI-to-EBus/Ethernet controller (PCIO) ASIC performs dual roles: PCI
bus-to-Ebus bridging and Ethernet control. The PCIO ASIC provides the electrical
272 Sun Enterprise 220R Server Service Manual
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January 2000, Revision A