SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
26.1.1 High-Level Description and Overview
The RF core receives high-level requests from the system CPU and performs all the necessary transactions to fulfill them. These requests are basically oriented to the transmission and reception of information through the radio channel, but can also include additional maintenance tasks such as calibration, test, or debug features.
As a general framework, the transactions between the system CPU and the RF core operate as follows:
- The RF core can access data and configuration parameters from the system RAM. This reduces the memory requirements of the RF core, avoids needless traffic between the different parts of the system, and reduces the total energy consumption.
- In a similar fashion, the RF core can decode and write back the contents of the received radio packet, together with status information, to the system RAM.
- For protocol confidentiality and authentication support purposes, the RF core can also access the security subsystem.
- In general, the RF core recognizes complex commands from the system CPU (CCA transmissions, RX with automatic acknowledge, and so forth) and divides them into subcommands without further intervention from the system CPU.
Figure 26-1 shows the external interfaces and dependencies of the RF core.
Figure 26-1 Limited RF Core Overview With External DependenciesEach block shown in Figure 26-1 performs the following functions:
System Side
- System CPU: Main system processor that runs the user's application, together with the high-level protocol stack (for a number of supported configurations) and eventually some higher-level MAC features for some protocols. The system CPU runs code from the boot ROM and the system flash.
- System RAM: Contains packet information (TX and RX payloads) and the different parameters or configuration options for a given transaction.
- Security Subsystem: Encompasses the different elements to provide protocol confidentiality and authentication.
- DMA: Optionally charged with the task of moving information from the radio RAM to the system RAM and vice versa, if direct CPU access is not used.
Radio Side
- Radio CPU: Main RF core processor. Receives high-level commands from the system CPU and schedules them into the different parts of the RF core.
- Modem, Frequency Synthesizer, RF Interfaces: This is the core of the radio, converting the bits into modulated signals and vice versa.