System Overview
In this project we designed an integrated circuit that works with several 555 timers to mimic the simple function of an electronic organ.
The circuit is able to play 5 notes in an octave range from middle C (C4) to middle A (A4) through a speaker. Moreover, it incorporates an auto play function
that play a simple melody automatically once turned on. Such device is useful and practical in ear training, music instrument tuning, etc.
The main purpose of this project is to learn and go through the complete design flow and get familiar with key aspects to fabricate Ice's with the
highest possible success. During the project, we strictly followed the following steps:
- List Specifications and Purposes
- High Level Implementation and Simulation
- Transistor Level Implementation and Simulation
- Layout
- Parasitic Extraction and Simulation
- Tape-out
- Printed Circuit Board (PCB) Design and Fabrication
- Post-silicon Verification
Figure 1 shows the system level block diagram of the IC. The analog part takes the output of a 555 timer and reshapes square waves to sine waves and amplifies them. The digital part takes five square waves in certain frequencies as inputs. It contains a counter, decoder and multiplexers, which are used to automatically choose the note to play.
Figure 2 shows the signal flow with both input and output configuration. The 555 timers are tuned to generate frequencies from C4 to A4, as shown in Table 1.
Users are allowed to either manually play these notes by pressing the specific push button on the PCB board or turn on auto play feature and let the circuit
to compose a simple melody.
