How fast can the SPI clock be set?
How many Mega/Byte per second can you transfer?
Did you ever try with some SPI slave that can support 100 Mhz like some NOR FLASH.
Thanks.

Hello,

1) in my memory, it can be set to something like 125MHz max because this is an even divider of the IO block clock (250MHz ?). Then 62.5MHZ (div=4), 41.6MHz (div=6) and 31.25MHz (div=8). I'll have to check.

But the PCB is not designed for high speeds and my loopback tests have shown that 31.25MHz is stable. I've seen boards using 64MHz though but they might require very careful layout and other RF best practices.

2) This is a tricky issue because I don't use DMA (yet). And I have discovered the hard way that the bandwith is actually 9 BITS PER BYTE because one bit is a dummy ! Bad, bad design. So a 31.25MHz clock will give you 3.47MB/s, if you can sustain the writing speed and keep the FIFO full at all times.

3) I haven't had this situation because my flasher uses long wires (ahem) and most of the time is wasted during erasure and writing of the data, not the transfer... So I use a clock in the 4-20MHz range.

Hope this helps