The CDC9842 is a high-performance clock synthesizer/driver that generates the system clocks necessary to support Pentium/82430X/82430VX and PentiumPro 82440FX chipsets. It provides four host-clock outputs (HCLKn) that are programmable to one of three frequencies (50 MHz, 60 MHz, or 66 MHz) via the SEL0 and SEL1 control inputs. Six PCI-clock outputs (PCLKn) are half the frequency of CPU clock outputs and are delayed 1 ns to 4 ns from the rising edge of the CPU clock. In addition, a universal serial bus (USB) clock output at 48 MHz (SBCLK) and three 14.318-MHz reference clock outputs (REF0, REF1, REF2) are provided. All output frequencies are generated from a 14.318-MHZ crystal input. A reference clock can be provided at the X1 input instead of the crystal input.
The CDC9842 is a high-performance clock synthesizer/driver designed to generate system clocks necessary to support Pentium™/82430X/82430VX and Pentium Pro 82440FX chipsets. It provides four programmable host-clock outputs, six PCI-clock outputs, one 48-MHz USB clock output, and three 14.318-MHz reference clock outputs.
| Host-clock output frequencies | 50 MHz, 60 MHz, or 66 MHz |
|---|---|
| USB clock output frequency | 48 MHz |
| Reference clock output frequency | 14.318-MHz |
It supports Pentium™/82430X/82430VX and Pentium Pro 82440FX chipsets.
They are programmable via the SELO and SEL1 control inputs.