The ACS8515 is a highly integrated, single-chip solution for hit-less protection switching of SEC clocks from Master and Slave SETS clockcards in a SONET or SDH Network Element. The ACS8515 has fast activity monitors on the inputs and will implement automatic system protection switching against master clock failure. A further input is provided for an optional standby SEC clock. The ACS8515 is fully compliant with the required specifications and standards. The ACS8515 can perform frequency translation from a SEC input clock distributed along a back plane to a different local line card clock, e.g. 8 kHz distributed on the back plane and 19.44 MHz generated on the line cards.