SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The McASP transmit formatting unit consists of three stages :
Figure 26-124 shows the transmit formatting unit.
The McASP transmitter supports serial formats of:
Hardware support for these serial formats comes from the programmable options in the bitstream format register - MCASP_TXFMT:
As shown in Figure 26-124, the data to the transmit format unit can come from the configuration port (CFG) or the data port (DATA). The selection is made through the MCASP_TXFMT[3] XBUSEL bit. According to port type selected, data transfer has different behaviour. For more details, refer to the Section 26.6.4.10.1.3, Transfers Through the DATA Port, and Section 26.6.4.10.1.4, Transfers Through the Configuration (CFG) Bus.
In the transmit format unit (TFU), the input data bits are first masked-off with the MCASP_TXMASK[31:0] XMASK contents. The masked data is then right-rotated to MCASP_TXFMT[2:0] XROT positions, to produce the output word for a TDM- or DIT- transmission.
The bit mask stage includes a full 32-bit mask register, allowing selected individual bits to pass through the stage unchanged or be masked off.