The problem is with your combination of the write address and the write strobes.
Your write addresses are 1,2,3.
But at the same time your write strobes are 0xFFFF thus all 16 byte lines are active. That is not allowed with the addresses of 1,2,3. The first 1, 2 and 3 byte strobes must be zero because you address is skipping those bytes.
See figure A3-13 ...
Those are for ordered sets. Ordered sets are only sent in between packets, never within a packet. Control characters and ordered sets are not allowed within packets; if they appear inside a packet then it's an error and the receiving MAC should drop the frame.
0x2d block: four control characters followed by an ordered set
0x55 block: two ordered sets
The way FPGAs are synthesised from VHDL through to implementation traverses so many steps, with automated decision making at every step obscuring the details, that it's very difficult to know beforehand for any non-trivial design how it's going to turn out.
If you made a very tightly constrained circuit, say the standard speed test of a large odd number of ...
Thats a wrong conclusion you are leading to , whenever you have designed the verilog/vhdl module in the constraints file you need to provide the following information,
-- Pin location constraints, IO Standard of IO pin(you can see the VCCO,VCC_AUX values in case of xilinx fpga similarly you can see for other FPGAs too),Slew ...
Your question is rather broad.
To start with: the good new is that you don't need to buy an FPGA board to find out how big your design is. The development tool will tell you. It will also tell you if you exceed the number of resources (Memories, LUTs, Registers, DSPs or I/O pins.) If it does not fit, you select a bigger FPGA in the tool setting, until you ...
For external signals that drives pins, std_logic should be used (and derivatives such as std_logic_vector, unsigned, signed). Alternatively bit
For internal signals, integer with range bounds, record, boolean, enumerated types, even character are synthesisable.
Time is not synthesisable except for calculating integer constants, floating point real also ...
The larger and more timing-critical your design, the more it should be aware of the underlying logic resources implementing it. This is true whether you’re working with an FPGA or ASIC flow. You will need to understand this to get the device to fit and to close timing.
FPGAs have hardware macros that help with this: RAM, special I/O, ALU/DSP blocks, ...
I solved it, I actually answered this with my question above.
I doubt that there will be another noobie like me having such a basic question but here it goes.
Once you declare a constraint name and implement it in a module. It seems that this constraint can not be renamed and passed from another module. It has to have the same name.
Example some pin named ...
Just connect your signal to the clock input and use an async reset:
module see_shorty (
output reg short_signal_seen
// You can make this negedge short_signal to detect a falling edge
// In the same way you can invert the reset signal
always @(posedge short_signal or posedge ...
How bout something like this? The clock is your local clock, common to all the flip flops. R is the reset (usually power on) for the FFs.
The glitch filter is optional.
Answer to OP's Question
S is just the SET input of the flip flop.