MK1493-02A

MK1493-02A Networking/PCI Clock Generator Description The MK1493-02A is a general purpose clock generator that provides an integrated clocking solution for PCI/Networking applications. It provides two pairs of differential CPU clocks, four PCI clocks, seven PCI_X clocks, two reference clocks, additional clock selectable from REF/50 MHz, and six pairs of SSTL2 DDR at 2.5 V. All complementary outputs operate only from a 2.5 V power supply. Input/Output Features Packaged in 56-pin TSSOP package 2 - Pairs of differential CPU clocks (differential current mode) 4 - PCI @ 3.3 V 7 - PCI_X @ 3.3 V 2 - REF @ 3.3 V, Fixed 6 - Pairs of differential SSTL2 DDR @ 2.5 V 1 - REF/50 MHz, selectable Spread spectrum for EMI control Supports SMBUS index read/write and blocks read/write operations Uses external 25 or 50 MHz crystal or clock CPU output jitter <125 ps PCI cycle to cycle output jitter <250 ps DDR cycle to cycle output jitter <150 ps Block Diagram PLL2 X1 XTAL OSC X2 PLL1 Spread Spectrum 2 CPU Divider PCI Divider REF(0:1) 50MHz/REF2 External capacitor required with crystal for accurate timing of clock w w w .D at aS he et 4U .c om OE FREQSEL FS (3:0) SDATA SCLK 4 Stop Delay 2 2 7 CPUCLKT (1:0) CPUCLKC (1:0) PCI_XCLK (6:0) Stop Delay Control Logic Config. Reg. AGP Divider DDR Divider Stop Stop Delay Delay 4 6 6 PCI (3:0) DDRT (5:0) DDRC (5:0) IREF CLK_STOPB PCI_STOPB SSEN MDS 1493-02A C 1 ● Revision 020204 tel (408) 297-1201 ● Integrated...