TIDUE74F April 2018 – March 2026
During IDLE there is no activity on the interface. The C28x must first setup a request. The T-Format API provides functions to setup each type of request:
The _setupCommand function creates a request data packet, loads the data to the SPI TX FIFO, and configures the CLB to generate the number of SPI clocks required to send the request and receive the response. Once setup is complete, the C28x starts the transaction by calling the PM_startOperation() function.
Refer to: Figure 2-2, marker (1).
When the transaction begins, the START_OPERATION signal is pulled high through GPREG. GPREG is the CLB's general purpose register allowing the C28x to directly control the tile's inputs. START_OPERATION remains high for one CLB CLOCK because the CLB's rising edge filter is enabled for the input. At this point, the main state machine (FSM_1) responds by moving the FRAME_STATE from IDLE to the TRANSMIT_DATA state.