SWRS045F January 2006 – November 2018 CC1021
PRODUCTION DATA.
The CC1021 device offers great flexibility for power management in order to meet strict power consumption requirements in battery-operated applications. Power down mode is controlled through the MAIN register. There are separate bits to control the RX part, the TX part, the frequency synthesizer and the crystal oscillator in the MAIN register. This individual control can be used to optimize for lowest possible current consumption in each application. Figure 5-27 shows a typical power-on and initializing sequence for minimum power consumption.
Figure 5-28 shows a typical sequence for activating RX and TX mode from power down mode for minimum power consumption.
NOTE
PSEL should be tri-stated or set to a high level during power down mode in order to prevent a trickle current from flowing in the internal pullup resistor.
TI recommends resetting the CC1021 device (by clearing the RESET_N bit in the MAIN register) when the chip is powered up initially. All registers that need to be configured should then be programmed (those which differ from their default values). Registers can be programmed freely in any order. The CC1021 device should then be calibrated in both RX and TX mode. After this is completed, the CC1021 device is ready for use. See the detailed procedure flowcharts in Figure 5-26 through Figure 5-28.
NOTE
The CC1020 device sub-routines are equally applicable for the CC1021 device.
TI recommends the following sequence:
After power up:
After calibration is completed, enter TX mode (SetupCC1020TX), RX mode (SetupCC1020RX) or power down mode (SetupCC1020PD).
From power-down mode to RX:
From power-down mode to TX:
Switching from RX to TX mode:
Switching from TX to RX mode: