1. DIGITAL ON/OFF
AM MODULATOR
AMIT R SHARMA
&
AKRAM SHAZAD

2. DIGITAL ON/OFF AM MODULATOR
AIM OF THE PROJECT
To Design a dedicated hardware module that performs on/off AM MODULATION.
The Modulated signal should be 8 bit sinus signal of MHz (carrier freq).
The Amplitude of the carrier signal should be configured from microcontroller.
The maximum clock freq is 100 MHz.

3. DIGITAL ON/OFF AM MODULATOR
What is on on/off AM Modulation. ?
Modulation is the process of facilitating the transfer of information
over a medium
The process of converting information so that it can be successfully
sent through a medium is called modulation
In amplitude modulation the amplitude of the signal is changed in
response to information and all else is kept fixed. (phase and freq)

4. DIGITAL ON/OFF AM MODULATOR
REQUIRED WAVEORMS
clk
i/p
o/p
No i/p

5. DIGITAL ON/OFF AM MODULATOR
OSCILLATOR
MODULATOR
Bit stream from base band coder
of 10ns.
The output is a Sine wave
With a carrier freq of MHz
WISHBONE INTERFACE

6. DIGITAL ON/OFF AM MODULATOR
Design of Oscillator
The clock freq is of 100 MHz and required freq of the carrier signal
should MHz hence we can have a maximum of 8 levels for
defining a sine wave.
COUNTER
clock
WAVEOUT
Reset
Enable
SINE
LOOKUP
TABLE

7. DIGITAL ON/OFF AM MODULATOR
/2  2
Amplitude
Time (ns) 

8. DIGITAL ON/OFF AM MODULATOR
Amplitude is controlled
By microcontroller using
Wishbone interface
Low Amplitude Reg
High amplitude Reg
Idle mode Reg L H
oscillator H
High amp
MUX 1
o/p L
Low amp 2
13.56 MHz
Low high 3
Idle low 4 s0 s1
00-idle low
01 idle high
”0”
”1”
Input data stream
0/1

9. DIGITAL ON/OFF AM MODULATOR Loop- Repeat forOther bit
i/p bit stream
IF i/p bit =1
IF No input
Check the
I/p bit
IF i/p bit=0
Sine wave
generator
Look up
table
select
S0S1=’11’
OUT- A
select
S0S1=’10
OUT- B
select
S0S1=’01’
OUT-C
select
S0S1=’00’
OUT- D
Loop- Repeat forOther bit
WISHBONE
High Ampl Reg
Const c1 A
MUX
SOS1
Low Ampl Reg
Const c2 B C
Idle Ampl Reg
Const c3 D
OUT

10. DIGITAL ON/OFF AM MODULATOR
RESULTS

11. DIGITAL ON/OFF AM MODULATOR
Results from Matlab

12. DIGITAL ON/OFF AM MODULATOR
RESULTS FROM VHDL
SYNTHESIS REPORT
HDL Synthesis Report
Macro Statistics
# FSMs : 1
# Multipliers : 2
8x8-bit multiplier : 2
# Adders/Subtractors : 2
7-bit adder : 1
1-bit addsub : 1
# Registers : 8
1-bit register : 6
8-bit register : 2
# Multiplexers : 3
1-bit 2-to-1 multiplexer : 1
8-bit 2-to-1 multiplexer : 1
16-bit 2-to-1 multiplexer : 1

13. DIGITAL ON/OFF AM MODULATOR
Device utilization summary
Selected Device: 3s4000fg900-5
Number of Slices: out of %
Number of Slice Flip Flops: out of %
Number of 4 input LUTs: out of %
Number of bonded IOBs: out of %
Number of MULT18X18s: out of %
Number of GCLKs: out of %
Timing Summary
Speed Grade: 5
Minimum period: 2.725ns (Maximum Frequency: MHz)
Minimum input arrival time before clock: 3.470ns
Maximum output required time after clock: ns
Maximum combinational path delay: 7.385ns

16. DIGITAL ON/OFF AM MODULATOR
CONCLUSION
The design has been successfully implemented by us.
The freq of the carrier signal comes out to be MHz.
The amplitude of the carrier signal is controllable.

17. DIGITAL ON/OFF AM MODULATOR
THANKS
FOR ATTENDING OUR PRESENTATION

18. DIGITAL ON/OFF AM MODULATOR
Questions