DM8168通过PCIe接收视频YUV帧,是否可以直接将接收地址设定为A8/M3VPSS共享内存区?
这样以避免,放到A8的内存区,再memcpy或者DMA_copy到M3VPSS区,增大对DDR3带宽的消耗。
BR!
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DM8168通过PCIe接收视频YUV帧,是否可以直接将接收地址设定为A8/M3VPSS共享内存区?
这样以避免,放到A8的内存区,再memcpy或者DMA_copy到M3VPSS区,增大对DDR3带宽的消耗。
BR!
你好,
不可行。DSP/M3无法直接访问PCIe的空间。
你可以查看DM8168 data sheet SPRS614 L3-Master-and-Slave System Interconnect Table.
不是让DSP/M3直接访问PCIe空间。
是让PCIe EP(FPGA)通过PCIe将视频YUV帧传到A8/M3VPSS shared region,我忘了是SR0,1还是几了。这样M3VPSS拿YUV帧就可以从shared region拿了,就不用A8再copy过去了,节省DDR带宽。
这样不行?
你好,
从下面的信息看,应该是可以的,从0x8000000开始的2GB空间都可以映射为inbound memory。
http://processors.wiki.ti.com/index.php/TI81XX_PSP_PCI_Express_Root_Complex_Driver_User_Guide#System_Resources
Inbound Memory
This memory is used to map TI81XX RAM so as to enable external masters (EP) to have access.
You can change this by updating ti81xx_pcie_resources data in arch/arm/mach-omap2/devices.c for "pcie-inbound0" resource:
{ /* Inbound memory window */ .name = "pcie-inbound0", .start = PHYS_OFFSET, .end = PHYS_OFFSET + SZ_2G - 1, .flags = IORESOURCE_MEM, },