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author | Yuchen Pei <me@ypei.me> | 2017-11-29 12:30:41 +0100 |
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committer | Yuchen Pei <me@ypei.me> | 2017-11-29 12:30:41 +0100 |
commit | a000308104aab27c2dde9a306f1bc654b2db4806 (patch) | |
tree | aecc628e14c1628b5714281437aba18680cdc27b /tools/builtInChips/Keyboard.hdl |
first commit
Diffstat (limited to 'tools/builtInChips/Keyboard.hdl')
-rw-r--r-- | tools/builtInChips/Keyboard.hdl | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/tools/builtInChips/Keyboard.hdl b/tools/builtInChips/Keyboard.hdl new file mode 100644 index 0000000..26ca5ed --- /dev/null +++ b/tools/builtInChips/Keyboard.hdl @@ -0,0 +1,23 @@ +// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: tools/builtIn/Keyboard.hdl
+
+/**
+ * The keyboard (memory map).
+ * Outputs the code of the currently pressed key.
+ *
+ * The built-in chip implementation has two side effects supplied
+ * by the simulator. First, the keyboard memory map is continuously
+ * being refreshed from the physical keyboard unit. Second, it
+ * displays a keyboard icon and data entry GUI.
+ */
+
+CHIP Keyboard {
+
+ OUT out[16]; // The ASCII code of the pressed key,
+ // or 0 if no key is currently pressed,
+ // or one the special codes listed in Figure 5.5.
+
+ BUILTIN Keyboard;
+}
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