SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
Error frames are similar to ping frames in that there are no data fields transmitted. Despite the naming of this frame as an “error frame,” the usage of it is up to the application, as no restrictions are placed on how and when this type of frame is transmitted. Table 25-7 shows the structure of an error frame.
Idle State | Preamble | SOF | Frame Type | Frame Tag | EOF | Postamble | Idle State |
---|---|---|---|---|---|---|---|
1111 | 1001 | 1111 | xxxx | 0110 | 1111 |
The structure of the error frame is the same as a ping frame. No data or CRC values are transmitted. The frame type is 1111 for all error frames, and the frame tag is defined by software in the TX_FRAME_TAG_UDATA register.
The receiver can detect if an error frame has been received based on the frame type field. Because of this, the receiver can read the incoming frame tag from the RX_FRAME_TAG_UDATA register and act on up to 16 different conditions.