Differences

This shows you the differences between two versions of the page.

--- motorola:68000 [2013/10/05 17:17] – [Visualisation] sarayan
+++ motorola:68000 [2025/08/04 21:24] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+FIXME: think data got moved here? https://og.kervella.org/m68k/
 ====== Die shots ======
   * [[http://dspnet.fr/~galibert/m68k/original|Original images]]
-  * [[http://dspnet.fr/~galibert/m68k/aligned|Rotated/scaled/roughly aligned images, 16000x14000 each]], the dist-*.sh scripts are the generating scripts
+  * [[http://dspnet.fr/~galibert/m68k/aligned|Rotated/scaled/roughly aligned images, 16000x14000 each]], the dist-*.sh files are the generating scripts
   * [[http://dspnet.fr/~galibert/m68k/map|Google map of the aligned images]]
@@ Line 9: / Line 11: @@
 ====== Vectorized layers ======
-  * [[http://dspnet.fr/~galibert/m68k/layers.7z|Compressed SVG, 42M uncompressed]], updated oct 3, md5 8dabcc191d1e9ef12fa6f7577c9f8a04.
+  * [[http://dspnet.fr/~galibert/m68k/layers.7z|Compressed SVG, 42M uncompressed]], updated oct 9
 The svg uses m68000-m-3.png as background, which should be in the same directory.  Beware that inkscape uses 5+G of ram to open and display it.
@@ Line 49: / Line 51: @@
 ====== Visualisation ======
-  * [[http://dspnet.fr/~galibert/m68k/mview.tar.bz2|mview]], linux/Qt program that displays the circuit and allows interactive simulation
-  * [[http://dspnet.fr/~galibert/m68k/mplay.tar.bz2|mplay]], linux program that does things with the circuit info (sanity checks, microcode dumping...)
+    * [[http://dspnet.fr/~galibert/m68k/mview.tar.bz2|mview]], linux/Qt program that displays the circuit and allows interactive simulation
-  * [[http://dspnet.fr/~galibert/m68k/pins.txt|pins.txt]], net naming file
+    * [[http://dspnet.fr/~galibert/m68k/mplay.tar.bz2|mplay]], linux program that does things with the circuit info (sanity checks, microcode dumping…)
+    * [[http://dspnet.fr/~galibert/m68k/pins.txt|pins.txt]], net naming file
 Note that the simulation program is essentially digital, with the side effect that relatively important things like the clock do not work.
+The text version of the schematics is composed of 3 parts:
+    * Header: one line: size x, size y, size ratio w.r.t traced image
+    * Nodes: one line with the node count followed by one line per node. A node id is its line number, starting at 0.
+      * Node type, t=nmos enh, d=nmos depl, v=vcc, g=gnd, p=pad, c=capacitor
+      * x position
+      * y position
+      * linked nets ids (t1/gate/t2 for t/d, t for v/g/p, t1/t2 for c)
+      * w/l ratio for transistors, surface for capacitors
+      * orientation (except for v/g)
+      * name
+    * Nets, one line with the node count followed by one line per net.  A net is is its line number, starting at 0.
+      * Number of reference points in the net drawing (beware, can be 0)
+      * x, y coordinates of each point, the id of a point is its number, starting at 0
+      * Number of lines in the net drawing (beware, can be 0)
+      * pid1, pid2 points ids of the start and end point of each line
+      * Number of big dots in the net drawing (beware, can be 0)
+      * points ids of the big dots
+      * Name of the net, often a number
+====== Schematics ======
+  * [[http://dspnet.fr/~galibert/m68k/schem|Google map of the generated schematics]], updated oct 9
+  * [[http://dspnet.fr/~galibert/m68k/schem.7z|svg and text version of the generated schematics]]
+  * [[http://dspnet.fr/~galibert/m68k/mschem.tar.bz2|Schematic generator, including the lua placement program]]
+  * [[http://dspnet.fr/~galibert/m68k/sview.tar.bz2|Qt schematic viewer, using the text version of the schematics]]
+  * [[http://dspnet.fr/~galibert/m68k/pads.txt|Pads placement/naming file]]
+The schematics are automatically generated from the previously generated files then the circuits are moved around by a lua program.  Run remap.lua to generate a new svg/text, run remap.lua toto to also generate the google map tiles.
+====== Schematics analysis ======
+===== Standard circuits =====
+==== Latch ====
+The 68000 uses a *lot* of latches.  They generally look like that:
+{{:motorola:latch.png?200|}}
+The latch value is set through the input line.  The value goes through two inverters then loops through a weak (l/w < 0.2) enhancement mosfet with terminal and gate tied.  That way the input drive can easily override it to set a new value.
+Both the output and its inverse are available, making it easy to build an amplifier afterwards.
+==== Register bit ====
+The register bits are described in patent 4,296,469.  They look like that:
+{{:motorola:register_bit.png?200|}}
+At the center two inverters are looped to keep the value.  Two independant vertical busses a and d are used for both reading and writing.  Reading is done by letting the bus float and connecting the memory to the bus with the a ctrl or the d ctrl line.  Writing is done by locking a value first on the bus then afterwards connecting the memory bit to the bus.
+====== References ======
+  * Die revs: http://siliconprawn.org/media/motorola/motorola_high-performance_internal_product_portfolio_overview.pdf
+  * Early die revs: https://books.google.com/books?id=kSDVBwAAQBAJ&pg=PA297&lpg=PA297&dq=mc68000+r9m&source=bl&ots=4BaXtdA_QH&sig=u8NOvZCee11l-q4PyF9jsElxanw&hl=en&sa=X&ei=HgluVciGB4W1sATrzILwDA&ved=0CDMQ6AEwAw#v=onepage&q=mc68000%20r9m&f=false
+    * J5H was first silicon, R9M was second