The DDR memory reference clock on the A10SoC development board is
differential. Currently the EMIF core it is configured for single-ended
configuration, which causes it to generate incorrect IOSTANDARD
constraints. Those incorrect constraints get overwritten again in
system_assign.tcl, so things are working, but this generates a warning when
building the design
Configure the EMIF core correctly and remove the manual constraint overwrite since
they are no longer necessary.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There is no guarantee that the external reset de-assertion is synchronous
to the sys_clk, yet the clock bridge marks the reset de-assertion as
synchronized to the clock. This can cause recovery or removal timing
violations for the registers affected by this reset signal and potentially
bring the system into an invalid state after the reset is de-asserted.
Mark the reset as not synchronized to the clock signal, this will make sure
that Qsys inserts the proper reset synchronizers where required.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Both the sys_hps.f2sdram_clock and the sys_dma_clk.clk signal are in the
same clock domain. They are both driven by the same clock. And even though
qsys is capable of detecting this it seems qsys interconnect is not able to
infer this and inserts a extra clock domain crossing bridge between the DMA
and the HPS AXI system memory interface.
To avoid this connect the sys_dma_clk.clk to the sys_hps.f2sdram_clock so
that all components are driven by the same qsys clock signal.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>