Texas Instruments SimpleLink CC2620 Technical Reference Manual page 1204

Modules
17.4.1.7 Running a Program
To execute a program on the sensor controller, the program image must first be uploaded to the AUX
RAM by the system CPU or DMA. The sensor controller is halted from reset, and does not receive any
clock.
There are two ways to have the CPU receive a clock and start executing its code:
• Write to the AON_WUC:AUXCTL.SCE_RUN_EN register
• Write to the AUX_SCE:CTL.CLK_EN register
Using the AON_WUC:AUXCTL.SCE_RUN_EN register bit is necessary if AUX_PD is being powered
down or up by the sensor controller, and the user wants to have the sensor controller restart without
interaction from the system CPU. TI recommends this way of using the sensor controller.
The AON_WUC:AUXCTL.SCE_RUN_EN register bit survives until the device enters shutdown, or there is
a system-wide reset.
The AUX_SCE registers are reset whenever AUX is reset or power-cycled. Otherwise, it has the same
functionality as the AON_WUC:AUXCTL.SCE_RUN_EN register bit.
17.4.1.7.1 Use Case – Periodic Wakeup
A typical use case is to wake up both AUX _PD and the sensor controller periodically, to execute a task
such as SPI or ADC sampling.
This wake up can be achieved, for example, by enabling the RTC channel 2 in continuous-compare mode
and setting it as a wake-up event vector in the AON_EVENT:AUXWUSEL register. When an RTC
compare event occurs on channel 2, this causes AUX to be powered on in active mode.
However, the sensor controller does not start to execute code until one of the four wake-up event vectors
(described in Section
setup as a wake-up vector to the sensor controller in the AUX_EVCTL:VECCFG0 and the
AUX_EVCTL:VECCFG1 registers.
During execution, the sensor controller event vector flag must be cleared to prevent it from restarting
again immediately at the same vector after a sleep instruction is issued.
When the task is finished executing and AUX_PD must power down, the sensor controller must make a
power-down request to the AON wake-up controller, and then the AUX_PD must be disconnected from
the MCU system bus. This process is described in
The wake-up event must be cleared before powering down to stop AUX from immediately powering on
again. The RTC has a dedicated interface for clearing channel 2, by writing to the
AUX_WUC:WUEVCLR.AON_RTC_CH2 register.
The AUX_PD must not request to power down until a read of the corresponding wake-up event flag
AUX_WUC:WUEVFLAGS register reads 0.
1204
AUX – Sensor Controller with Digital and Analog Peripherals
17.4.2.1.2, Sensor Controller Events) are triggered, so RTC channel 2 must also be
Copyright © 2015, Texas Instruments Incorporated
Section 17.5, Power Management.
SWCU117C – February 2015 – Revised September 2015
www.ti.com
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