SNAU279A July 2022 – September 2022
The SYNC/SYSREF/1-PPS page shows all the SYSREF block settings and allows the user to configure the GPIO1 or GPIO2 for continuous SYSREF or 1-PPS clock output.
The SYSREF divider output signals can be replicated on either GPIO1 and GPIO2 to provide additional single-ended, 3.3-V CMOS clocks after start-up if desired. To configure the SYSREF/1PPS output replication the GPIO must be enabled as an output (GPIOx_OUTEN = 1) and one of the SYSREF output to GPIO replication sources must be active. The SYSREF replication source comes from any one of the SYSREF dividers in use from OUT0/1, OUT4/5, OUT6/7, OUT/9, OUT10/11 or OUT12/13 by register programming (OUT_x_y_SR_GPIO_EN = 1 and GPIO_SYSREF_SEL to the appropriate OUT_x_y). The GPIOx replicated SYSREF output will be a continuous frequency. Pulsed SYSREF mode is not supported for the GPIOx replica outputs.