Magic Frequently Asked Questions

Author: Patrick Testerman

• Instructions for combining layouts and pad frame:
  If you simply read in the CIF pad file and draw or copy your layout on top of it, Magic will treat this as an embedded cell linked to the external CIF file, which will cause problems later on, so you need to copy everything to a new layout file.
  1. Copy the pad frame CIF file, and the two magic layout files to the same directory.
  2. Start magic without loading anything by simply typing "magic"
  3. Read the CIF pad file in by typing ":cif read 40pc22x22_stuffed_analog"
  4. Press "v" to see the entire frame. It should appear as a black box with the file name on the inside. To expand the cell so you can see the actual design, place the (white) box around the entire cell (black box) and press "x" (the macro for 'expand'). The entire pad layout should appear.
  5. Now open a new window which will contain the combined layouts by typing ":open newfilename" where newfilename is the name of your final combined layout file. A blank new window should appear with the heading 'newfilename [NOT BEING EDITED]' at the top.
  6. You need to make the new window the active edit window in order to copy things into it. Place the Box anywhere in the new window and press 's' for select. The magic xterm window should give the message 'Selected cell is newfilename.' Now make this the edit window by typing ':edit' The window title should change to 'newfilename EDITING newfilename'
  7. In the window containing the pad frame, place the box around the entire padframe and press 'a' (for select area). After a second, the entire padframe should be selected.
  8. Move the cursor to the newfilename window and press 'c' to copy the padframe to the new window. Press 'C' and 'v' to unselect the pads and view the entire cell. The new window should now have a copy of the pad frame which you can edit and save.
  9. Next, open two more windows containing your and your partner's amplifier layouts by typing ':open mylayout' (do not type the .mag extension after the filename)
  10. 1Copy the amplifer layout to the newfilename window in the same way the padframe was copied. Repeat this for you partner's amplifier.
• Connecting to the pads:
  The pads actually consist of the pad itself, plus two diodes to Vdd and Gnd which serve as a form of protection if the pad voltage should spike above Vdd or below Ground. If you look at the pad, you will see the pad along with a bunch of stuff next to it. There is a sort of channel running from the pad through the other stuff to the inside of the pad frame. In the center of channel is a METAL1 wire. This is what you need to connect to. To more easily see the wire, switch to the wiring tool by pressing space. The cursor should change to an arrow, and the xterm window will display a message. Point to the thin stripe at the middle of the channel, near the inside of the pad frame and click the left button. A small white box should appear and the xterm window should display a message, 'Using metal1 wires 4 units wide.' If it lists a different type of wires, click the left mouse button again until you get METAL1 wires. Now point the cursor in the inside of the pad frame, straight in from the pad and click the right mouse button. Magic should extend the wire towards the inside of the frame so you can see the wire. To connect to the wire, simply draw an adjoining metal1 wire.