This bus provides the data currently being written to the external memory. APP_DATA_WIDTH is 2 × nCK_PER_CLK × DQ_WIDTH when ECC is disabled (ECC parameter value is OFF) and 2 × nCK_PER_CLK × (DQ_WIDTH – ECC_WIDTH) when ECC is enabled (ECC parameter is ON).
PAYLOAD_WIDTH indicates the effective DQ_WIDTH on which the user interface data has been transferred.
PAYLOAD_WIDTH is DQ_WIDTH when ECC is disabled (ECC parameter value is OFF).
PAYLOAD_WIDTH is (DQ_WIDTH - ECC_WIDTH) when ECC is enabled (ECC parameter is ON).