APPENDIX C
Functional Description
This appendix provides a functional description for the following:
Section C.1 “System Unit” on page 249
Section C.1.14 “Power Supply” on page 274
Section C.1.17 “Main Logic Board” on page 277
The following items are not supported on the Sun Enterprise 220R server:
Graphics and imaging card
Diskette drive
Audio card
C.1 System Unit
The system unit is an UltraSPARCport architecture (UPA)-based multiprocessor
machine that uses peripheral component interconnect (PCI) as the I/O bus. The CPU
modules, U2P ASIC (UPA-to-PCIbridge), and UPAgraphics cards communicate with
each other using the UPAprotocol. The CPU modules and the U2P ASIC are UPA
master-slave devices. The UPAgraphics cards are UPA slave-only devices. The QSC
ASIC routes UPArequest packets through the UPA address bus and controls the flow
of data using the XB9+ ASIC. For further information, see the following items:
Section C.1.1 “UPA”on page 252
Section C.1.2 “PCI Bus” on page 253
Section C.1.3 “UltraSPARCII Processor” on page 254
Section C.1.4 “Memory System” on page 255
Section C.1.5 “Graphics and Imaging” on page 259
249