生成时钟 (generated clock) 是从称为主时钟 (master clock) 的另一个现有时钟衍生的。它通常用于描述逻辑块对主时钟执行的波形变换。由于生成时钟定义取决于主时钟特性,因此必须首先定义主时钟。为显式定义生成时钟,必须使用create_generated_clock 命令。 自动衍生时钟 大部分生成时钟都是由 Vivado 时序引擎自动衍生
set_clock_groups -logically_exclusive -group clk0 -group clk1 仅存在路径A、B或C之一的情况:clk0 和/或 clk1 与多路复用时钟直接交互。为了保留时序路径A、B和C,无法直接向 clk0 和 clk1 直接应用约束。而是改为必须将其应用于多路复用器的扇出中需要额外的时钟定义的时钟部分。 create_generated_clock ...
create_generated_clock -name clk_sck -source [get_pins -hierarchical *axi_quad_spi_0/ext_spi_clk] [get_pins STARTUP/CCLK] -edges {3 5 7} set_input_delay -clock clk_sck -max 7 [get_pins STARTUP/DATA_IN[*]] -clock_fall set_input_delay -clock clk_sck -min 1 [get_pins START...
create_generated_clock -name Clkout -source [get_pins ODDR_inst/C] -combinational [get_pins ODDR_inst/Q]This entry was posted in EDA, FPGA on 15. January 2017. random postings from Xilinx forums Leave a reply This finds all the cells of a certain type but it doesn’t check if the...
“if a control signal on this register goes inactive at the same time as the clock signal triggers, which signal will be evaluated by the simulator first?” But the result was that different Verilog simulators might generate different results, which is always somewhat disconcerting to the end ...
(posedge clock)); initial structures may also not be converted. If you do not specify the bit width of the number, the system may default it to a larger value (such as 32 bits), which may result in a very large logic gate-level netlist, some of which are unnecessary, which will ...
1. Create a top module that has clk and reset as input and has two outputs call them clk_out1 and clk_out2. The module creates two instances of the clock module clk_div that we created above. One will divide the clock by 10 and other will divide it by 20. Create test bench to ...
A parameter with an undesired value can lead to both very obvious errors (mismatch in size of a wire to a port) or to very subtle errors (e.g. a parameter used to count a number of clock cycles before reporting an error is set too large to ever get triggered). For this reason, it...
Synchronous logic blocks are generated using special identifiers in the sensitivity list. Here we only want to update on the positive edge of the clock, so we use posedge. This will generate a synchronous circuit that implements x every clock cycle. ...
Power estimation will be inaccurate until this is corrected. Resolution: Please specify clocks using create_clock/create_generated_clock for sequential elements. For pure combinatorial circuits, please specify a virtual clock, otherwise the vectorless estimation...