SWRU543B January 2019 – June 2025 CC3230S , CC3230SF , CC3235MODS , CC3235MODSF , CC3235S , CC3235SF
The CC32xx Wi-Fi microcontroller is a multiprocessor system-on-chip with several subsystems independently cycling between active and sleep states (application processor, network processor, WLAN-MAC, and WLAN-PHY) for optimal energy use. The activities of various subsystems are tied to the data and management traffic. In absence of events and traffic, all the systems are typically in a sleep state (LPDS).
The timing of sleep and wakeup do not need to be synchronized across subsystems. For example, in an idle-connected case, when the association to the AP is maintained most of the time, the WLAN subsystem is in LPDS and wakes up periodically for short intervals, only to listen for any incoming beacon packets and delivery pending messages from the AP (apart from occasional keep alive packet transmissions). While this repeats in multiples of the beacon period (104 mS), the application processor may implement its own sleep strategy with a different periodicity.
An advanced power management scheme has been implemented at the CC32xx chip level. This scheme handles the asynchronous sleep-wake requirements of multiple processors and Wi-Fi radio subsystems in a way that is transparent to the software, yet energy efficient.
The chip-level power-management scheme is such that the application program is unaware of the power state transitions of the other subsystems. This approach insulates the user from the real-time complexities of a multiprocessor system; it improves robustness by eliminating race conditions and simplifies the application development process.
As a result, the power mode of the chip can be different from the sleep state of the application software code. For example, when the application code requests for LPDS mode it is granted immediately; however, if the network processor or WLAN is active at that time, the chip does not enter LPDS mode until they are finished. In that case, the application processor is held under reset, which produces a safe result for the software, regardless of when the digital logic gets power-gated and when the voltage drops to 0.9 V. Similarly, on wake event for a particular subsystem, the chip as a whole transitions into active state (VDD_DIG = 1.2 V, 40-MHz XOSC and PLL-enabled) and then only that subsystem is awakened from LPDS. The other subsystems are held in reset until their respective wake events.
Table 15-1 shows the feasible combinations of power states between the application processor and the network (including WLAN) subsystems). See the CC3235S and CC3235SF SimpleLink™ Wi-Fi®, Dual-Band, Single-Chip Solution data sheet or CC3230S and CC3230SF SimpleLink™ Wi-Fi® 2.4GHz Wireless MCU with Coexistence data sheet for details of current consumption for these combinations.
| Application Processor (MCU) Software State | Network Processor and WLAN Software State | Resulting Power State of Chip, Core Logic Voltage, and Clock |
|---|---|---|
| ACTIVE | ACTIVE | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| ACTIVE | SLEEP | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| ACTIVE | LPDS (Fake-LPDS) | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| SLEEP | ACTIVE | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| SLEEP | SLEEP | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| SLEEP | LPDS (Fake-LPDS) | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| LPDS (Fake-LPDS) | ACTIVE | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| LPDS (Fake-LPDS) | SLEEP | ACTIVE (1.2 V, 80 MHz, 32 kHz) |
| LPDS (Fake-LPDS) | LPDS (Fake-LPDS) | LPDS (True-LPDS) (0.9 V, 32 kHz) |
| Request For HIBERNATE | Don't Care | HIBERNATE (0 V, 32 kHz) |
Figure 15-2 shows the high-level architecture of the CC32xx SoC-level power management.