Vhdl-Code-for-Adc0804-Comparator-and-Parity-Generator.pptx

VHDL code

1. VHDL CODE FOR ADC0804 , 4-BIT MAGNITUDE COMPARATOR AND PARITY GENERATOR Presented by:- APARNA Department of Electronics Engineering (VLSI & ES)

2. TOPICS ADC0804 ADC FEATURES PIN DIAGRAM & DISCRIPTION ADC0804 INTERFACE SCHEMATIC & TIMING DIAGRAM VHDL CODE & SIMULATION RESULT PARITY GENERATOR INTRODUCTION VHDL CODE & SIMULATION RESULT 4-BIT MAGNITUDE COMPARATOR INTRODUCTION VHDL CODE & SIMULATION RESULT

3. ADC Analog-to-digital converter (ADC) is a device which can convert analogue voltage to digital numbers so that microcontrollers and microprocessors can handle and process the data. ADC are the most widely used devices for data acquisition. ADC has n-bit resolution , where n can be 8, 12, 16 or even 24 bits.

4. The higher -resolution ADC provides a smaller step size . Step size is the smallest change that can be recognized by ADC Vcc is the reference voltage of ADC with n-bit resolution. Table : Resolution versus Step Size for ADC (if Vcc = 5V)

5. ADC0804 IC

6. ADC0804 Features Single channel ,8-bit parallel ADC module Easy to interface with all Microprocessors or works Stand alone . Differential analog voltage inputs. 0V to 5V analog input voltage range with single 5V supply. On chip Clock available .

7. Digital output various from 0 to 255. When Vref = 5V, for every 19.60mV of analog value there will be rise of one bit on digital side (Step size) Available in 20-pin PDIP, SOIC packages. A common, low-cost ADC, compatible with a wide range of microprocessors. T here are many faster ADCs available with more resolution, this device is ideal for applications that do not require a high degree of accuracy. ADC0804 requires up to 100 µs to convert an analog input voltage into a digital output code.

8. ADC0804 PIN DIAGRAM

9. PIN DESCRIPTION Pin No Function Name 1 Activates ADC; Active low ; used if more than 1 ADC module is used. By default grounded Chip select 2 Input pin; High to low pulse brings the data from internal registers to the output pins after conversion Read 3 Input pin; Low to high pulse is given to start the conversion Write 4 Clock Input pin; to give external clock. Clock IN 5 Output pin; Goes low when conversion is complete Interrupt 6 Analog non-inverting input Vin(+) 7 Analog inverting Input; normally ground Vin(-) 8 Ground(0V) Analog Ground 9 Input pin; sets the reference voltage for analog input Vref/2 10 Ground(0V) Digital Ground 11 8 bit digital output pins D7 12 D6 13 D5 14 D4 15 D3 16 D2 17 D1 18 D0 19 Used with Clock IN pin when internal clock source is used Clock R 20 Supply voltage; 5V Vcc

10. TIMING DIAGRAM FOR ADC0804

11. ADC0804 INTERFACE INTR/EOC ADC 8-BIT OUTPUT ADC0804 FPGA RD/OE WR/SC Analog input ADC OUTPUT (LED) CLK

12. VHDL CODE FOR ADC0804

13. SIMULATION RESULT

14. PARITY GENERATOR A Parity Generator is a Combinational Logic Circuit that Generates the Parity bit in the Transmitter. A Parity bit is used for the Purpose of Detecting Errors during Transmissions of binary Information. It is an Extra bit Included with a binary Message to Make the Number of 1’s either Odd or Even.

15. Two Types of Parity In Even Parity , the added Parity bit will Make the Total Number of 1’s an Even Amount. In Odd Parity , the added Parity bit will Make the Total Number of 1’s an Odd Amount.

16. PARITY GENERATOR TRUTH TABLE

17. VHDL CODE FOR ODD PARITY

18. SIMULATION RESULT

19. 4-BIT MAGNITUDE COMPARATOR Compare two multi-bit binary numbers The comparison of two numbers outputs: A>B, A=B, A<B

20. LOGIC USED IN VHDL CODE i n_1=_ _ _ _ i n_2=_ _ _ _ ‘0’ -> unsigned bit vector Comp_type ‘1’-> signed bit vector in_1= 0 _ _ _ in_1 = 1 _ _ _ in_2= 0 _ _ _ in_2 = 1 _ _ _ in_1= 1 _ _ _ in_1= 0 _ _ _ in_2 = 0 _ _ _ in_2= 1 _ _ _

21. VHDL CODE FOR COMPARATOR

22. SIMULATION RESULT

23. THANK YOU