I have this project where I have to design a tachometer using VHDL. The thing is I m pretty new to the field of electronic projects and I m very new to VHDL.
The project asks me to count the Rotations/per Minute from a motor.
It has to be in the range 19-98 RPM, the measurement time is 1.1s, and the display resolution is 0.1 .
What I have to do next is when i press a button it will count the pulses for 1.1s and then display the result. [During counting the display will be OFF].
Sorry for the long post but the first problem resumes to this. How do i design a clock divider so I can get a period of 1.1s.
I have a basic clock divider code where i count the rising edges and then i change the state of clock. But how many edges i have to count?
Code:
ENTITY CLKDIV IS
PORT(
CLK: IN STD_LOGIC;
CLKOUT: OUT STD_LOGIC
);
END CLKDIV;
ARCHITECTURE DIV OF CLKDIV IS
BEGIN
PROCESS (CLK)
VARIABLE COUNT: INTEGER RANGE 0 TO ???? :=0;
VARIABLE STATE: STD_LOGIC := '1';
BEGIN
IF(RISING_EDGE (CLK)) THEN
IF(COUNT= )THEN
COUNT:=0;
STATE:= '1';
ELSE
COUNT := COUNT+1;
END IF;
IF(COUNT=)
STATE:= NOT STATE;
END IF;
END IF;
CLKOUT <= STATE;
END PROCESS;
END DIV;