Intel® 865G/865GV Chipset Datasheet - download.intel.nl - Intel

Functional Description5.8 ClockingThe GMCH has the following clocks:• 100/133/200 spread spectrum, Low voltage (0.7 V) Differential HCLKP/HCLKN for FSB• 66.667 MHz, spread spectrum, 3.3 V GCLKIN for Hub Interface and AGP• 48 MHz, non-spread spectrum, 3.3 V DREFCLK for the Display frequency syntheses• 12 pairs SDRAM output clocks (SCMCLK_x[5:0] and SCMDCLK_x[5:0]# for both channelsA and B)• Up to 85 MHz, 1.5 V DVOBC_CLKINT for TV-Out mode only.The GMCH has inputs for a low voltage, differential pair of clocks called HCLKP and HCLKN.These pins receive a host clock from the external clock synthesizer. This clock is used by the hostinterface and system memory logic (Host Clock Domain). The graphics engine also uses this clock.AGP and hub interface are synchronous to each other and are driven from the 66 MHz clock.The Graphics core and display interfaces are asynchronous to the rest of the GMCH.Figure 15. Intel ® 865G Chipset System Clocking Block DiagramProcessorLow Voltage Differential ClocksLow Voltage Differential ClocksDDRDifferential Pairs266/333/400 MHz DDR100/133/200 MHz133/166/200 MHzAGP 8XHostPLLGMCHAND/ORDDRDifferential PairsDIMM 0DIMM 1DIMM 2DIMM 3CorePLLDPLL24–350 MHz48 MHz DOTCK 409Main PLL400 MHz66 MHz66 MHzBufferSection/233 MHz33 MHz33 MHz33 MHz33 MHz33 MHz33 MHz33 MHzPCI Slot 0PCI Slot 1PCI Slot 2PCI Dev 1PCI Dev 2PCI Dev 3PCI Dev 4PCI Dev 514 MHzOSC48 MHzPLL33 MHz66 MHzITP100/133/200MHz48 MHz USB14 MHz33 MHz APICIntel ®ICH548 MHz DOTIntel ® 82865G/82865GV GMCH Datasheet 183