SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
26.2 Radio Doorbell
The radio doorbell module (RFC_DBELL) is the primary means of communication between the system CPU and the radio CPU, also known as command and packet engine (CPE). The radio doorbell contains a set of dedicated registers, parameters in any of the RAMs of the device platform, and a set of interrupts to both the radio CPU and to the system CPU.
In addition, parameters and payload are transferred through the system RAM or the radio RAM. If any parameters or payload are in the system RAM, the system CPU must remain powered. However, if everything is in the radio RAM, the system CPU may go into power-down mode to save current.
During operation, the radio CPU updates parameters and payload in RAM and raises interrupts. The system CPU can mask out interrupts so that it remains in idle or power-down mode until the entire radio operation finishes.
Because the system CPU and the radio CPU share a common RAM area, ensure that no contention or race conditions can occur. This is achieved in software by rules set up in the radio hardware abstraction layer (HAL).
Figure 26-2 shows the relevant modules for information exchange between the CPUs.
Figure 26-2 Hardware Support for the HAL