SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Two memory regions are associated with the QSPI. The first memory region is dedicated to the configuration port. Using this memory region, all internal registers can be programmed and serial transfers made from the four supported external SPI devices. The L3_MAIN start address at which the configuration port is available is 0x4B30 0000. The second memory region is associated mainly with the memory-mapped port and is used for communication directly with one of the four supported external SPI devices. This memory region starts at 0x5C00 0000 and ends at 0x5FFF FFFF L3_MAIN address.
The CTRL_CORE_CONTROL_IO_2[10:8] QSPI_MEMMAPPED_CS bit field provides a functionality for remapping the previously described address space which starts at 0x5C00 0000 L3_MAIN address to one of the four supported chip selects or to the configuration registers. The CTRL_CORE_CONTROL_IO_2 register resides in the CTRL_MODULE_CORE.
It is important to keep in mind that the configuration port provides an access to all the QSPI registers listed in Table 24-284. These are configuration registers and also four data registers. The configuration registers are used to configure typical SPI and serial flash memory settings and the four data registers are used for read and write operations. When communicating with an external SPI device (but not an SPI flash memory) the SPI_CORE module should be used and the data exchanged is available thorough these four data registers, which can be accessed only through the configuration port. When a communication with an external SPI flash memory is desired, the memory-mapped port should be used.
In other words, to read from an external SPI flash memory, first configure the QSPI through the configuration port and then perform a read through the memory-mapped port.