SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The sequence of control transactions that are performed by the UDMA on the Read/Write VBUSM interface during transmit is to read a Transfer Request record from a logical work queue and to then return a corresponding Transfer Response record to a separate logical work queue when all the transfers in the request have been completed. This sequence repeats for as long as Transfer Request records are provided on the work queue. The exact details of the operations that are involved are covered in the TI DMA Architecture specification (see Section 10.1).
The sequences of data transactions that are performed by the UDMA on the Write Only Memory interface during receive can be described as a sequence of piecewise linear write transfers whose starting addresses are each sequentially calculated based on loops and offsets given in the Transfer Request record. A TR can have up to 4 levels of nested transfer sets where each set can have a different element count and stride between elements. TR record formats are described in detail in the Transfer Request format specification.