Is synplify pro worth it code#

The resulting process would look very similar to your second process above, with everything wrapped in an if (rising_edge(clk)) then, and every occurence of nstate replaced with pstate. You can put the whole machine and the state transitions into one clocked process.

Is synplify pro worth it code#

In addition to these, the two-process state machine design shown in your code is not necessary. By avoiding latches altogether, you avoid having to think about this sort of problem. For any internal interfaces, I would work to avoid the latch existing at all, but the same technique might apply. If it is ok to have inferred clocks, how can I let the tool know of it? What period constrain can I provide for such inferred clocks? How can I determine a meaningful period for such inferred clocks?ДЇor the case of an external interface, the level-sensitive input will have some minimum pulse width, and you can use this to create a period constraint that constitutes the worst possible case of how that signal might toggle. There are exceptions, but this should be the starting point.Д¤. Doing this will give you predictable timing results and make it easier to write constraints. You would have to simulate your design or probe it on board to make sure that the function is equivalent in your particular case, but the basic philosophy in the FPGA should be that any assignment other than simple a <= b and c or some_vec <= smaller_vec & another_bit uses a clocked process. This will infer a flip-flop for offset_val. Use a clocked process that contains the assignment. If it not ok to have inferred clocks in the design, how can I fix this by coding the logic differently? In your case it looks like it should be quite easy to avoid a latch.ДЈ. One example where latches must be used would be if some external interface had to use a level sensitive input of some kind. Latches in general should be avoided unless there is a strong reason to have them, because they usually provide poor timing performance, and can more easily result in hazards and races in the design. Is it alright to have such statements in the design? Does the presence of inferred clocks indicate a bad design practice? Your gate signal at that point is using clock resource, but ultimately it is derived from another 'data' signal, as opposed to a 'real' clock.Дў. In any FPGA I have used, this will be implemented by activating a 'latch' mode in a normal flip flop, using the 'clock' pin as the 'gate'. This line does not describe anything happening when pstate is not s2. Why is there an inferred clock on pstate in this design? If you are creating an ASIC or using some other flow, a different answer might apply.ДЎ. You have added an FPGA tag, so I will answer from an FPGA perspective. If it is ok to have inferred clocks, how can I let the tool know of it? What period constrain can I provide for such inferred clocks? How can I determine a meaningful period for such inferred clocks?.If it not ok to have inferred clocks in the design, how can I fix this by coding the logic differently?.Is it alright to have such statements in the design? Does the presence of inferred clocks indicate a bad design practice?.Why is there an inferred clock on pstate in this design?.

I am looking for a few clarifications in this regard.

However, my logic doesnвЂ™t work correctly. When I put the same statement inside a clocked process, the inferred clock warning disappears. I realised that this assignment statement is causing the inferred clock in the design (but donвЂ™t know why). The state s2 is used for capturing the value of ctr1 before it resets to 0. This offset value is stored to a signal vector, as can be seen in the last line of the code.

The value of ctr1 determines how much later is ctr2 started (in terms of 25MHz clock period), referred to as the offset. ctr1 stops counting when ctr2 is enabled. In the first phase ctr1 is run, which is then followed by ctr2. The counters are run when there are no system failures. The logic contains two counters вЂ“ ctr1 and ctr2. P_ctr1 : process(reset_n_in, clk_25mhz_in) Save the counter1 value and start counter2 If (sys_fail = '0' and restart_ctr = '1') then p_fsm_clk : process(reset_n_in, clk_25mhz_in) I traced back to the part of the code where the warning is being generated and the same is reproduced here for reference. |В FoundВ inferredВ clockВ counter_unit| pstate_inferred_clockВ withВ periodВ 10.00ns.В PleaseВ declareВ aВ user-definedВ clockВ onВ objectВ 'n:bcu_ins.ctr_ins.pstate' The synthesis report gives me the following warning on inferred clocks. I am trying to synthesize a design in VHDL into a ProASIC3 FPGA using the Synplify Pro tool.