System Architecture; Block Diagram - Compaq AlphaServer DS20 Service Manual

1.4

System Architecture

An Alpha microprocessor chip is used in this system. The CPU, memory, and the
I/O modules are physically connected to the system board and logically connected
through a switch-based interconnect implemented in a cross-bar switch chipset.
Figure 1-4 Block Diagram
Command, Address, and Control lines for each Memory Array
C chip
Control lines for D chips
Probe/
Probe/
CAPbus
Addr.
Addr.
CMD/
Addr.
CPU 1
(optional)
CMD/
Addr.
CPU 0
CPU
Data
Bus
B cache
B cache
1-8 AlphaServer DS20 Service Manual
P chip
64 bit PCI
P chip
64 bit PCI
PAD
Bus
Memory
8 D chips
Up to 2
Memory
Banks
Data
Bus
1 or 2
Memory
Banks
PKW1400-98