SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
To facilitate ping-pong buffer management, EVE allows the local EDMA and VCOP view of IBUFLA versus IBUFLB, and IBUFHA versus IBUFHB memories to be aliased into the same address ranges. ARP32 and System accesses (through OCP target port) always use the unique/256-KB address map for IBUF memory accesses.
Having a VCOP accesses and EVE_MEMMAP[0] VCOP_ALIAS = 0x1 limits VCOP data memory view to 128KB, with A and B sets aliased to the same address range, depending on the MMR ownership bits (EVE_MSW_CTL). When EVE_MEMMAP[0]VCOP_ALIAS = 0x0, VCOP uses the full 256 KB address. The EVE_MEMMAP[0]VCOP_ALIAS bit has no effect on how other initiators (ARP32, EDMA or SYS) see the VCOP memories. The VCOP view truth table is shown in Table 8-27.If IBUFLA/IBUFHA is set (while VCOP owned), then the memory switch points to the IBUFHA/IBUFLA memory and IBUFHB/IBUFLB is a "don't care". If VCOP accesses address that is shown in gray in Table 8-27, that is reported as an error.
Having local EDMA accesses, when EVE_MEMMAP[4] LCL_EDMA_ALIAS = 0x1, limits local EDMA data memory view to 128KB, with A and B sets aliased to the same address range, dependent on the MMR ownership bits (EVE_MSW_CTL). When EVE_MEMMAP[4] LCL_EDMA_ALIAS = 0x0, EDMA uses the full 256-KB address. The EVE_MEMMAP[4] LCL_EDMA_ALIAS bit has no effect on how other initiators detect the VCOP memories. Table 8-28 is the local EDMA truth table. If IBUFHA or IBUFLA is cleared (while EDMA/system owned), then the memory switch points to the IBUFHA or IBUFLA memory and IBUFHB/LB bit is a don't care bit. If ARP32, EDMA, or system accesses an address shown in gray, then that is reported as an error.
The ALIAS and ownership register are modified when the system is initializated, or between major modes of operation when no memory transactions are ongoing. If the mode changes while accesses are in progress, then a given address may change from valid to reserved (or viceversa), or a given address can change from one memory to another.
ARP32 and system accesses (including the system EDMA) always view the expanded 256-KB unique addresses for access to IBUF memories.
When a memory switch error is detected, the physical address is captured. IBUFLB address is 0x40007 0000 even if in aliased mode.