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>
While things seem to work fine with only specifying the the IO standard for
the positive side of differential signals Quartus will issue a warning
about incomplete constraints if the IO standard is not specified for the
the neagtive side as well. To avoid these warnings add the missing
constraints.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fix a copy and paste error and specify the IO_STANDARD for all gpio_bd_i
rather than twice for half of them.
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>
Lars-Peter Clausen
Rejeesh Kutty
Istvan Csomortani
AndreiGrozav
Adrian Costina
dbogdan