1. Project Step 2 – A single bit slice of the ALU
Structural Modeling 1
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

2. Copyright 2006 - Joanne DeGroat, ECE, OSU
Project Step Overview
Write the Entity and Architecture for the carry chain bit slice block of the multifunction ALU
Use it and the generic unit from Project Step 1 to generate a single slice of the ALU
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

3. Detailed of code you write
The Entity for the Carry Chain Unit
The Architecture (dataflow style) of the Carry Chain Unit
An Entity and Architecture for the single slice of the ALU
This will require external interface for all inputs and outputs of a single slice
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

4. Copyright 2006 - Joanne DeGroat, ECE, OSU
Signals needed
The single slice interface
Data – A, B
P block control – P(0 to 3)
K block control – K(0 to 3)
Carry In
Carry Out
R block control – R(0 to 3)
Results output – F
Internal Signals for P and K, Pint and Kint
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

5. Plus component instantiations
To instantiate a component that has been compiled into the library
First declare it in the declarative region of the architecture
This is easiest done by simply copying the Entity interface of the unit and changing ENTITY to COMPONENT, delete the IS, and change the END unit_name to END COMPONENT
Also, do a configuration also in this region
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

6. Copyright 2006 - Joanne DeGroat, ECE, OSU
The configuration
For these first examples just use
FOR ALL : unit_label_used_in_component_decl USE ENTITY WORK.unit_name(arch_name);
Will see later that ALL can be changed to specific instantiation labels.
The unit_label must match that of the component declaration when you instantiate it in the Architecture
Assuming that you have called your library WORK
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

7. Copyright 2006 - Joanne DeGroat, ECE, OSU
The instantiation
Once declared and configured the unit can be use between the BEGIN and END of the ARCHITECTURE (instantiated)
Provide a label for the instantiation
Use named signals to wire to the inputs and outputs.
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU

8. Copyright 2006 - Joanne DeGroat, ECE, OSU
Turn in requirements
Turn in: (Carmen drop box)
A copy of your code
Your code will be very similar to every other students but it won’t be exact.
A copy of the complete waveform and a copy zoomed into 0 to 650ns
A copy of the listing file after you have “collapsed deltas” and set the radix to hex
1/8/ L5 PS2 Structural Slice
Copyright Joanne DeGroat, ECE, OSU