SWRS045F January 2006 – November 2018 CC1021
PRODUCTION DATA.
In synchronous mode, the DCLK pin on the CC1021 device can be used to give an interrupt signal to wake the microcontroller when the PLL is locked.
PD_MODE[1:0] in the MAIN register should be set to 01. If DCLK_LOCK in the INTERFACE register is set to 1 the DCLK signal is always logic high if the PLL is not in lock. When the PLL locks to the desired frequency the DCLK signal changes to logic 0. When this interrupt has been detected write PD_MODE[1:0] = 00. This will enable the DCLK signal.
This function can be used to wait for the PLL to be locked before the PA is ramped up in transmit mode. In receive mode, it can be used to wait until the PLL is locked before searching for preamble.