Compaq deskpro en series Manual De Usuario
Chapter 4 System Support
Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Third Edition - September 1998
4-28
4.5
SYSTEM CLOCK DISTRIBUTION
The system uses a Cypress CY2280 or compatible part for generation of most clock signals.
Table 4-17 lists the system board clock signals and how they are distributed.
Table 4-17 lists the system board clock signals and how they are distributed.
Table 4–17. Clock Generation and Distribution
Table 4-17.
Clock Generation and Distribution
Frequncy/Signal
Source
Destination
66, 100 MHz
(CPUCLK) [1]
(CPUCLK) [1]
CY2280
Processor, 82443 N. Bridge
66 MHz
North Bridge
AGP Slot
48 MHz
“
82371 S. Bridge, 87307 I/O Cntlr.
33 MHz (PCICLK)
“
PCI Slots, 82371 S. Bridge
14.31818 MHz
Crystal
W48C67
14.31818 MHz
CY2280
South Bridge, ISA slots
8.33 MHz (BCLK)
South Bridge
ISA slots
32.77 KHz
Crystal
South Bridge
NOTE:
[1] Depending on processor speed (refer to
Chapter 3, “Processor/Memory Subsystem”).
Chapter 3, “Processor/Memory Subsystem”).