ZHCSHN9A February 2018 – April 2018 LMK05028
PRODUCTION DATA.
Each output driver can automatically mute or squelch its clock when the selected output mux clock source is invalid, as configured by its CH_x_MUTE bit. If the selected clock source is derived from a PLL post-divider output, the source can be invalid based on the LOL status of each PLL by configuring the APLL and DPLL mute control bits (MUTE_APLLx_LOCK, MUTE_DPLLx_LOCK, MUTE_DPLLx_TCXO). If the selected source is a bypass clock (XO or TCXO), the source is invalid when a LOS is detected on the input. The mute level can be configured per output channel by its CHx_MUTE_LVL bits, where the mute level depends on the configured output driver type (Differential/HCSL or LVCMOS). The mute level for a differential or HCSL driver can be set to output common mode, differential high, or differential low levels. The mute level for a LVCMOS driver pair can be set to output low level for each of its outputs (P and N) independently. When auto-mute is disabled or bypassed (CH_x_MUTE = CHx_MUTE_LVL = 0), the output clock can have incorrect frequency or be unstable before and during the VCO calibration if derived from a PLL. For this reason, the mute bypass mode should only be used for diagnostic or debug purposes.