29.6.5 TDM Format - Reception and Transmission Sequence
In Time Division Multiplexed (TDM) format, the number of data slots sent or received within each frame will be (CLKCTRLn.NBSLOTS + 1).
By configuring the CLKCTRLn register (CLKCTRLn.FSWIDTH and CLKCTRLn.FSINV), the Frame Sync pulse width and polarity can be modified.
By configuring SERCTRLm, data bits can be left-adjusted or right-adjusted in the slot. It can also configure the data transmission/reception with either the MSB or the LSB transmitted/received first and starting the transmission/reception either at the transition of the FSn pin or one clock period after.
Data bits are sent on the falling edge of the Serial Clock and sampled on the rising edge of the Serial Clock. The FSn pin provides a frame synchronization signal, at the beginning of slot 0. The delay between the frame start and the first data bit is defined by writing the CLKCTRLn.BITDELAY field.
The Frame Sync pulse can be either one SCKn period (BIT), one slot (SLOT), or one half frame (HALF). This selection is done by writing the CLKCTRLn.FSWIDTH field.
The number of slots is selected by writing the CLKCTRLn.NBSLOTS field.
The number of bits in each slot is selected by writing the CLKCTRLn.SLOTSIZE field.
The length of transmitted words can be chosen among 8, 16, 18, 20, 24, and 32 bits by writing the DATASIZE field in the Serializer Control register (SERCTRLm).
If the slot allows more data bits than the number of bits specified in the SERCTRLmDATASIZE bit field, additional bits are appended to the transmitted or received data word as specified in the SERCTRLmEXTEND bit field. If the slot allows less data bits than programmed, the extra bits are not transmitted, or received data word is extended based on the EXTEND field value.