We're trying to get GPMC to transfer 16 words (16bit) from our GPMC connected FPGA into DDR.
FPGA can read/write single transfers fine.
0x50000060 GPMC_CONFIG1(0) =0x28001200;
0x50000070 GPMC_CONFIG5(0)) =0x00060606;
Changing settings to below I can generate what looks like a burst from GPMC for a single 32 bit read. See CS0_r32_burst_waveform.pdf
4846.CS0_r32_burst_waveform.pdf
However, if I access same location from DMA the number of GPMC clocks double for some reason. See CS0_DMA_burst_waveform.pdf
6735.CS0_DMA_burst_waveform.pdf
Can anyone tell me if the problem is my GPMC settings?
FPGA config: NOR, 16bit, CS0, mux'd Address/Data, FCLK=100Mhz/FCLK divider=1, no wait, starting address 0x10000000.
Register settings below:
0x50000010 =8;
0x5000001c =0;
0x50000040 =0x1FF0;
0x50000048 =0;
0x50000050 =0x2;
0x50000054 =0X101;
0x50000060 GPMC_CONFIG1(0) =0x79001200;
0x50000064 GPMC_CONFIG2(0)) =0x00000081;
0x50000068 GPMC_CONFIG3(0)) =0x11110191;
0x5000006c GPMC_CONFIG4(0)) =0x00000012;
0x50000070 GPMC_CONFIG5(0)) =0x01060615;
0x50000074 GPMC_CONFIG6(0)) =0x020202c2;
0x50000078 GPMC_CONFIG7(0)) =0x00000f50;
Thanks in Advance!