Hi,Experts
Currently the GPMC multiple read/write is not working, any advice?
GPMC single read/write is working.
We are trying to get GPMC multiple read to work first.
- NOR Flash like, asynchronous and synchronous devices
- Non-multiplexed attached device
- Read/Write Synchronous
- 16bit/16words Multiple Read
- GPMC_FCLK=300MHz/GPMC_CLK=100MHz with the core clock set at 900MHz.(GPMCFCLKDIVIDER=2h)
- GPMC is run from DSP
1. I found a post on E2E that says if you want to work with 16words Multiple,
you need to access it with DMA, is that correct?
e2e.ti.com/.../66ak2g12-why-can-t-gpmc-of-66ak-work-as-16words-burst-access
2. Does it matter whether DMA is EDMA_0 or EDMA_1?
3. The qdma_test() in the edma3 sample (edma3_lld_2_12_05_30E) worked.(DDR->DDR memory copy)
This qdma_test() is modified as follows.
- The source address is the address of the GPMC. The destination address is the DDR
acnt=4,bcnt=8,ccnt=1
- EDMA3_DRV_SYNC_A
- Set Source Address to EDMA3_DRV_W16BIT
- Source Transfer Mode is set to EDMA3_DRV_ADDR_MODE_FIFO
(32 bytes of data are about to be read.)
The waveforms of each GPMC signal in that case are attached.
When the modified qdma_test() is executed, the waveforms shown in Figure 1 appear a total of 8 times.
（I understand that bcnt=8,ccnt=1 so 8 times out）
4. I think I can read 16bit/16words with just one waveform in Figure 1, but what does it mean
that qdma_test() executes bcnt*ccnt times?
Is this the wrong sample to refer to?
* waveform:GPMC_MultipleRead.pdf
Best Regards,
Hidekazu
