Read/Write-specific swacc
SystemRDL defines the swacc
property, but it does not distinguish between
read and write operations - it is asserted on all software accesses.
Similarly, the spec defines swmod
which gets asserted on software writes,
but can also get asserted if the field has on-read side-effects.
What if you just wanted a plain and simple strobe that is asserted when software
reads or writes a field? The rd_swacc
and wr_swacc
UDPs provide this
functionality.
Properties
These UDP definitions, along with others supported by PeakRDL-regblock can be
enabled by compiling the following file along with your design:
regblock_udps.rdl
.
- rd_swacc
If true, infers an output signal
hwif_out..rd_swacc
that is asserted when accessed by a software read operation. The output signal is asserted on the same clock cycle that the field is being sampled during the software read operation.
- wr_swacc
If true, infers an output signal
hwif_out..wr_swacc
that is asserted as the field is being modified by a software write operation.