US Patent 10572255 Stream engine with element promotion and decimation modes

A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces address of data elements. A steam head register stores data elements next to be supplied to operational units for use as operands. A promotion unit optionally increases date element data size by an integral power of 2 either zero filing or sign filling the additional bits. A decimation unit optionally decimates data elements by an integral factor of 2. For ease of implementation the promotion factor must be greater than or equal to the decimation factor.