From 9c600c32654ed2d729ec46170cf3f149e261d3cf Mon Sep 17 00:00:00 2001 From: Holger Vogt Date: Sat, 12 Oct 2019 19:06:46 +0200 Subject: [PATCH] short description of branch contents --- README.optran | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 README.optran diff --git a/README.optran b/README.optran new file mode 100644 index 000000000..180dd1280 --- /dev/null +++ b/README.optran @@ -0,0 +1,36 @@ +Adding transient simulation top generate the operating point of a circuit + +The operating point of a circuit has to be established before a transient, ac, +or noise simulation may be started. + +The procedure, as found in cktop.c is as follows: +1) Iterate the matrix with the starting values +If this fails: +2) Start gmin stepping +If this fails: +3) start source stepping + +If this again fails, bail out. + +In tghis branch a fourth method is added: +4) Start a transient simulation for a specific amount of time. + Keep all data local. Keep the matrix values as an + operating point for the simualtion following. +If this fails, finally stop. + +The time for transient is determined a priori. If a transient +simulation follows, choose 100 time the TSTEP value. If an ac +or noise simulation follows, take the invers of the starting +frequency divided by 10 as the optran simulation time. + +A method to stop the op transient simulation, when all nodes +have become stable, might be good, but has not yet been implemented. + +Step 1 may be skipped by +option noopiter + +Step 2 may be skipped by +option gminsteps=0 + +Step 3 may be skipped by +option srcsteps=0