From e0998d590caaec71fe103391cf8dc422ddccf412 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Mon, 13 Dec 2021 13:27:58 -0700
Subject: [PATCH] DmpPi::evalDmpEqns nan proofing

Signed-off-by: James Cherry <cherry@parallaxsw.com>
---
 dcalc/DmpCeff.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dcalc/DmpCeff.cc b/dcalc/DmpCeff.cc
index a4bdee88..574697a8 100644
--- a/dcalc/DmpCeff.cc
+++ b/dcalc/DmpCeff.cc
@@ -960,6 +960,9 @@ DmpPi::evalDmpEqns()
 
   double t_vth, t_vl, slew;
   gateDelays(ceff, t_vth, t_vl, slew);
+  if (slew == 0.0)
+    throw DmpError("eqn eval failed: slew = 0");
+
   double ceff_time = slew / (vh_ - vl_);
   if (ceff_time > 1.4 * dt)
     ceff_time = 1.4 * dt;