The W83L177R is a 10 outputs SDRAM clock buffer for 2-DIMMs models incorporate with W83L197R-16 which is the clock synthesizer especially for the 100MHz models such as Intel BX chipsets.(Refer the datasheet fo Winbond W83L197R-16) The W83L177R receives the clock from chipset by the Buffer_In pin and provides almost zerodelay (less than 4ns propagation delay) SDRAM buffer outputs for the 10 SDRAM clocks which are synchronous with the CPU clock outputs priovided by W83L197R-16. The clock skew between any two clock outputs is less than 250ps and the output buffer impedance is about 15 ohms. The W83L177R also provides I2C serial bus interface to program the registers to enable or disable each SDRAM clock outputs.