The OCE signal in the SP(X)9B primitive is intended to control the
built-in output register. The documentation states that this port is
invalid when READ_MODE=0 is used. However, it has been experimentally
established that you cannot simply apply VCC or GND to it and forget it
- the discrepancy between the signal on this port and the signal on the
CE port leads to both skipping data reading and unnecessary reading
after CE has switched to 0.
Here we force these ports to be connected to the network, except in the
case where the user controls the OCE signal using non-constant signals.
Also:
* All PIPs for clock spines are made inaccessible to the common router
- in general, using these routes for signals that have not been
processed by a special globals router is fraught with effects that
are difficult to detect.
* The INV primitive has been added purely to speed up development -
this primitive is not generated by Yosys, but is almost always
present in vendor output files.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
Now the clock router can place a buffer into the specified network,
which divides the network into two parts: from the source to the buffer,
routing occurs through any available PIPs, and after the buffer to the
sink, only through a dedicated global clock network.
This is made specifically for the Tangnano20k where the external
oscillator is soldered to a regular non-clock pin. But it can be used
for other purposes, you just need to remember that the recipient must be
a CLK input or output pin.
The port/network to set the buffer to is specified in the .CST file:
CLOCK_LOC "name" BUFG;
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
And also fix the clock router to allow (with a warning) non-dedicated
routing in case of false detection of clock wires.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
- experiment with notifyBelChange as an auxiliary cells reservation mechanism;
- since HCLK pips depend on the coordinates, and not on the tile type,
the tile type is copied if necessary;
- information about supported types of differential IO primitives has
been added to the extra information of the chip;
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
Add processing IO located on the sides of some chips. These are IOBUF,
which are converted into IBUF and OBUF not by fuses, but by signaling to
OE.
Also added the creation of a Global Set / Reset for all chips, instead
of a list of tile types, information from the apicula database is used,
and minor fixes.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
- The global router is modified to work out the routing of PLL outputs and inputs;
- Added API function to change wire type after its creation - there was
a need to unify all wires included in the node at the stage of node
creation, when all wires have already been created.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
Shamelessly adapted gatecat's router.
Very early version, not yet puzzled with recognizing clock sources and
controlling the type of wires involved.
Signed-off-by: YRabbit <rabbit@yrabbit.cyou>
