By setting the AXI controler interface type from axi4 to axi4lite we can use
the normal toplevel file with only a simple modification to add the awprot
and arprot signals.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
We can remove the Altera toplevel wrapper if we switch the axi4 control bus
to axi4lite and add the few missing signals that are required by the Altera
interconnect to both the control and the data buses.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This is unused and unneeded. The AXI interconnect will make sure that a
peripheral only gets requests that are meant for it, there is no need to
check the address in the peripheral itself.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Make sure that if a read and a write request arrive on the very same clock
cycle to only accept one of them. The simple solution chosen here is to only
accept the write request when this happens and delay the acceptance of the
read request until the write request is finished.
This solution is not fair since a write request will always take precedence,
which in theory allows the write bus to starve the read bus. But in practice
we should never see that many write requests that we are unable to answer
the read request.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Wait for the master to accept the response for the current transaction
before we allow a new transaction to start.
This fixes problems in case the master is not ready to accept the response
when we make it available.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
We must make sure that the response ID is the same as the request ID when we
accepted the request. Otherwise we might respond with the wrong ID and the
system will lockup.
Also set rlast to 1 instead of 0.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Otherwise we get timing errors for the reset signal that is generated in the
50MHz clock domain, but used in the VGA PLL clock domain.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>