这是因为"always"关键字通常用于描述硬件描述语言(HDL)中的行为模型,而"assignment"操作符用于将值分配给变量。 在硬件描述语言(如Verilog和VHDL)中,"always"关键字用于定义组合逻辑或时序逻辑的行为。它指定了一段代码应该在特定条件下执行。"assignment"操作符用于将值分配给变量或信号。 由于"always"关键字和"assig...
sinceclk‘eventyields abooleanvalue, andclkis of typebit. Theandoperator is not defined for this mixture of operand types. Instead, we compare theclkvalue with ‘1’ using the “=” operator, as shown in the if statement. VHDL-87 In VHDL-87, the‘last_valueattribute for a composite sign...
In a PID controller, the PID parameters are determined based on performance measurements. An autotuning technique uses a mathematical model of the process’ input/output relationship to tune PID parameters. This technique is often supplemented by the input of an experienced operator. These autotuning ...