This document describes the preliminary features of the integrated core logic frequency generator produced by Cypress Semiconductor Corporation. The frequency generator features maximized EMI suppression using Cypress's Spread Spectrum technology, low jitter, and tightly controlled clock skew. It is a highly integrated device that provides clocks for CPU, core logic, and SDRAM. The frequency generator also includes multiple copies of different frequency outputs and supports power-down control and an SMBus interface.
The W219B is a highly integrated spread‑spectrum frequency timing generator that supplies a variety of clock sources, including CPU, PCI, SDRAM, and USB clocks, for Intel‑based systems. It features selectable frequencies via pin strapping and offers EMI reduction through spread‑spectrum modulation.
The device includes a two‑pin serial data interface for configuring internal registers, detailed pin definitions, and a 48‑pin SSOP package. Power‑down control allows the device to enter a low‑power mode where all PLLs are disabled and clock outputs are held low.
| 48‑MHz Clock Output | 48 MHz |
|---|---|
| Cycle‑to‑Cycle Jitter (CPU/SDRAM) | 250 ps |
| Maximum Block Write Data Bytes | 32 bytes |
A block write can transfer up to 32 data bytes.
The W219B features a two‑pin serial data interface for configuring internal registers.