From a000308104aab27c2dde9a306f1bc654b2db4806 Mon Sep 17 00:00:00 2001 From: Yuchen Pei Date: Wed, 29 Nov 2017 12:30:41 +0100 Subject: first commit --- tools/builtInChips/Keyboard.hdl | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 tools/builtInChips/Keyboard.hdl (limited to 'tools/builtInChips/Keyboard.hdl') 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; +} -- cgit v1.2.3