Intel SERVER BOARD SDS2 - Manual (Page 84)

Clock/Voltage Generation and Distribution Intel® Server Board SDS2
Revision 1.2
Order Number: A85874-002
70
7. Clock/Voltage Generation and Distribution
7.1 Clock
All buses on the SDS2 Server Board operate using synchronous clocks. Clock
synthesizer/driver circuitry on the Server Board generates clock frequencies and voltage levels
as required, including the following:
• 133 MHz at 2.5 V logic levels: For CPU1, CPU2, HE-SL, DIMM Sockets and the ITP port
• 66 MHz at 3.3 V logic levels: For HE-SL, CIOB, P64-B and P64-C PCI slots
• 48 MHz at 3.3V logic levels: For CSB5’s USB
• 33.3 MHz at 3.3 V logic levels: For CIOB, CSB5 and on-board PCI devices and slots
• 16.67 MHz at 2.5 V logic levels: For processor and the CSB5 APIC bus clocks
• 14.318 MHz at 3.3V logic levels: For CSB5 and Video
Other clock sources on the SDS2 Server Board generates:
• 80 MHz at 3.3 V logic levels: For Ultra 360 SCSI Controller
• 32.768 MHz at 3.3 V logic levels: For SIO and BMC
• 14.318 MHz at 3.3 V logic levels: for main clock generator
For information on processor clock generation, see the CK133-WS Synthesizer/Driver
Specification.
The following figure illustrates clock generation and distribution on SDS2 Server Board.