From ce7f1d7dbf7a51a5c3828d7a18ea40ba87bb0fcf Mon Sep 17 00:00:00 2001
From: Stefan Frederik <stefan.schippers@gmail.com>
Date: Mon, 4 Jan 2021 17:24:57 +0100
Subject: [PATCH] added rotate operator in logic function description

---
 src/hilight.c                                 |  7 +++++
 src/xschemrc                                  |  2 +-
 xschem_library/xschem_simulator/fa_1.sym      |  2 +-
 .../xschem_simulator/simulate_ff.sch          | 29 +++++++++++++++----
 4 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/hilight.c b/src/hilight.c
index 30d4dcbf..535d8d2c 100644
--- a/src/hilight.c
+++ b/src/hilight.c
@@ -915,6 +915,13 @@ int eval_logic_expr(int inst, int output)
         stack[sp] = stack[sp - 1];
         sp++;
       }
+    /* rotate down: bottom element goes to top */
+    } else if(str[pos] == 'r') {
+      if(sp > 1) {
+        int tmp = stack[0];
+        for(i = 0 ; i < sp - 1; i++) stack[i] = stack[i + 1];
+        stack[sp - 1] = tmp;
+      }
     } else if(str[pos] == 'x') { /* exchange top 2 operands */
       if(sp > 1) {
          int tmp = stack[sp - 2];
diff --git a/src/xschemrc b/src/xschemrc
index 7c9805b3..3d671218 100644
--- a/src/xschemrc
+++ b/src/xschemrc
@@ -224,7 +224,7 @@
 # set terminal {xterm -geometry 100x35 -fn 9x15 -bg black -fg white -cr white -ms white }
 #### lxterminal is not OK since it will not inherit env vars: 
 #### In order to reduce memory usage and increase the performance, all instances
-#### of the terminal are sharing a single process. LXTerminal is part of LXDE
+#### of the lxterminal are sharing a single process. LXTerminal is part of LXDE
 
 ###########################################################################
 #### EDITOR
diff --git a/xschem_library/xschem_simulator/fa_1.sym b/xschem_library/xschem_simulator/fa_1.sym
index 628e3802..957aeaff 100644
--- a/xschem_library/xschem_simulator/fa_1.sym
+++ b/xschem_library/xschem_simulator/fa_1.sym
@@ -1,7 +1,7 @@
 v {xschem version=2.9.9 file_version=1.2 }
 G {}
 K {type=primitive
-function3="0 1 ^ 2 & 0 1 & |"
+function3="0 d 1 d r & r r ^ 2 & |"
 function4="0 1 2 ^ ^"
 format="@name @@A @@B @@CIN @VGND @VNB @VPB @VPWR @@COUT @@SUM @prefix\\\\fa_1"
 template="name=x1 VGND=VGND VNB=VNB VPB=VPB VPWR=VPWR prefix=sky130_fd_sc_hd__ "
diff --git a/xschem_library/xschem_simulator/simulate_ff.sch b/xschem_library/xschem_simulator/simulate_ff.sch
index 1df957a3..9674c5a4 100644
--- a/xschem_library/xschem_simulator/simulate_ff.sch
+++ b/xschem_library/xschem_simulator/simulate_ff.sch
@@ -11,15 +11,21 @@ L 4 100 -1470 100 -1390 {}
 L 4 200 -1470 200 -1390 {}
 L 4 100 -1570 100 -1490 {}
 L 4 200 -1570 200 -1490 {}
+L 4 1710 -1640 1710 -1360 {}
+L 4 1710 -1360 1750 -1360 {}
+L 4 1750 -1370 1750 -1360 {}
+L 4 1750 -1370 1770 -1360 {}
+L 4 1750 -1350 1770 -1360 {}
+L 4 1750 -1360 1750 -1350 {}
+L 4 1710 -1600 1750 -1600 {}
+L 4 1750 -1610 1750 -1600 {}
+L 4 1750 -1610 1770 -1600 {}
+L 4 1750 -1590 1770 -1600 {}
+L 4 1750 -1600 1750 -1590 {}
 B 12 3920 -2840 4640 -1540 {}
+P 5 9 1800 -300 1800 -220 1790 -230 1810 -180 1830 -230 1820 -220 1820 -300 1810 -290 1800 -300 {fill=true}
 T {7 Segment Display driver
 and base-10 counter} 1540 -3130 0 0 2.5 2.5 {}
-T {This example shows Xschem (very simple) simulation abilities
-Ctrl-Click to start simulation.
-Xschem will be only partially responsive during simulation.
-Will run for 100 iterations.
-If you need to stop:
-Simulation -> Forced stop tcl scripts} 1730 -750 0 0 1.5 1.5 {}
 T {Cyan: Uninitialized or unknown (X)} 3210 -1190 0 0 1.5 1.5 {layer=1}
 T {Signal colors:} 3130 -1290 0 0 1.5 1.5 {}
 T {Blue: Logic level low (0)} 3210 -1090 0 0 1.5 1.5 {layer=12}
@@ -60,6 +66,17 @@ T {Segment 4} 1190 -960 0 0 1 1 { layer=4}
 T {Segment 5} 1190 -560 0 0 1 1 { layer=4}
 T {Segment 6} 1190 -240 0 0 1 1 { layer=4}
 T {Truth Table} 10 -1730 0 0 1.5 1.5 {layer=4}
+T {This example shows Xschem (very simple) logic simulation abilities
+Ctrl-Click to start simulation.
+Xschem will be only partially responsive during simulation.
+Will run for 100 iterations.
+If you need to stop:
+Simulation -> Forced stop tcl scripts} 1720 -810 0 0 1.3 1.3 {}
+T {select this net and:
+- press '0' to set to logic '0' value
+- press '1' to set to logic '1' value
+- press '2' to set to logic 'X' value
+- press '3' to set to toggle 1->0, 0->1, X->X} 1680 -1880 0 0 0.7 0.7 {}
 N 2340 -2250 2340 -2170 { lab=#net1}
 N 2220 -2250 2340 -2250 { lab=#net1}
 N 2220 -2270 2220 -2250 { lab=#net1}