The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design Languages >> Verilog-AMS >> $table_model($abstime, ...) is very slow in Cadence Spectre
https://designers-guide.org/forum/YaBB.pl?num=1446218912

Message started by cheap_salary on Oct 30^th, 2015, 8:28am

Title: $table_model($abstime, ...) is very slow in Cadence Spectre
Post by cheap_salary on Oct 30^th, 2015, 8:28am

I created custom RF signal generator from I_PWL_File and Q_PWL_File using Verilog-A $table_model() like following.

Code:

analog begin
@(initial_step) begin
omega = `M_TWO_PI * frf;
theta0 = `M_PI * init_phase / 180.0;
end //initial_step

Isig = $table_model($abstime, I_PWL_File);
Qsig = $table_model($abstime, Q_PWL_File);

theta = omega * $abstime + theta0;
V(plus, minus) <+ scale * ( Isig*cos(theta) - Qsig*sin(theta) );
end //analog

However this signal generator is very slow when it is used in Cadence Spectre compared to using two "analoglib/vpwlf".

Is it limitation of $table_model() ?