The STC5230 single chip solution of timing source in SDH, SONET and synchronous Ethernet network elements from Connor-Winfield Corporation is fully compliant with ITU-G.813 and Telcordia GR1244 and GR253. It accepts 12 reference inputs, and it generates nine independent synchronized output clocks. Reference input frequencies are automatically detected, and inputs are individually monitored for quality. Active reference selection may be manual or automatic. All reference switches are hitless. Synchronized outputs may be programmed for a variety of SONET and SDH as well as synchronous Ethernet frequencies. Two independent timing generators, T0 and T4, provide the essential functions for Synchronous Equipment Timing Source (SETS). Both timing generators support master/slave operation for redundant applications. The STC5230 is capable of field upgrade with optional external EEPROM or via the bus interface.