🥼 Lab enhancing designs --- Enhance 2 system designs (#236)

Author: jameshughes89

site/index.rst

@@ -105,6 +105,7 @@ Office Hours
     labs/comparisons/comparisons
     labs/decoding-instructions/decoding-instructions
     labs/decoding-instructions/decoding-instructions-registers
+    labs/system-design/enhancing-designs
 
 
 

site/labs/system-design/enhancing-designs.rst

@@ -0,0 +1,87 @@
+*****************
+Enhancing Designs
+*****************
+
+* Feel free to use your laptop
+* You are strongly encourage to work with others
+
+    * When you get stuck, ask those sitting around you for help
+    * Get used to working together in the labs
+    * Peer teaching and peer learning has been empirically shown to be very effective
+
+
+
+Including Hardware
+==================
+
+For this part of the lab, use the ESAP digital file
+:download:`from here. <../../topics/control-logic/esap_alu_ram_output_pc_instruction_control.dig>`
+
+
+#. Include the hardware for ``AND``, ``OR``, and ``NOT`` operations to the ESAP system
+
+    * These operators will work similar to addition to subtraction in the existing design
+
+        * Apply the operator to the contents of the A and B registers, and store the result in the A register
+        * ``NOT`` only works on the contents of the A register
+
+
+#. These new operators require control signals
+
+    * Connect these new control signals to the control logic loop up table
+
+
+
+Control Logic
+=============
+
+For this part of the lab, use the script for generating the control logic patterns
+:download:`from here. <../../topics/control-logic/create_control_logic_patterns_for_look_up_table.py>`
+
+
+#. Although the new control logic is connected, ensure the look up table has the correct number of outputs
+
+    * Ensure the number of outputs from the look up table includes the new control signals
+
+
+#. Update the contents of the look up table to allow for three new machine code instructions
+
+    * An instruction for each of the operators allowed by the new hardware
+    * Use the 3 unused patterns for these instructions
+    * Use the Python script to create a new hex file for the look up table
+
+
+#. Write machine code programs to ensure each of these new instructions work properly
+
+
+
+Enhancing the Previous Lab
+==========================
+
+#. If not already completed, finish the design from the previous lab
+
+
+16 Bit Bus
+----------
+
+#. In a separate circuit, create a design for a 16 bit bus using
+
+    * RAM with an 8 bit address space and 8 bit addressability (:math:`265 \times 8` bits)
+    * A counter
+    * Two 8 bit instruction registers
+
+        * Even counter values retrieve data from even RAM addresses, and odd values retrieve from odd memory addresses
+        * Fetching from RAM takes 2 clock cycles
+        * One of the two 8 bit registers will always store bit patterns from the even or odd memory addresses
+        * The output from these two 8 bit registers make up the 16 bit bus
+
+
+#. Add this 16 bit bus to the design from the previous labs
+
+    * Include it in the design such that bit patterns can be written to RAM and executed automatically
+
+        * The bit patterns as discussed in previous labs
+
+
+    * Not all of the 16 bits will be needed when interfacing with the previous design
+    * The program counter enable will likely need to be controlled carefully