Serial Communication with  PC and CPLD

Universal Asynchronous Receiver Transmitter (UART) is a kind of serial
communication protocol; mostly used for short-distance, low speed, low-cost data exchange between computer and peripherals. UARTs are used for asynchronous serial data communication by converting data from parallel to serial at transmitter with some extra overhead bits using shift register and vice versa at receiver. Serial communication reduces the distortion of a signal, therefore makes data transfer between two systems separated in great distance possible. It is generally connected between a processor and a peripheral, to the processor the UART appears as an 8-bit read/write parallel port. The UART implemented with VHDL language can be integrated into the FPGA to achieve compact, stable and reliable data transmission various designs are found in literatures for UART as different systems have different requirements and attributes which require data communication between its functional units. In recent years the researchers have proposed various UART
designs like automatic baud rate synchronizing capability predictable timing
behavior to allow the integration of nodes with imprecise clocks in time-triggered real-time systems recursive running sum filter to remove noisy samples integration of only core functions into a FPGA chip to achieve compact, stable and reliable data transmission to avoid waste of resources and decrease cost programmable logic to enable interfacing between asynchronous communications protocols and PC having serial ports.

4 Digit Stop Watch using CPLD

Counting the External Pulses Coming from any source such as Visitors entry in room or from encoder which is connected to motors for determining the motor speed is essential in the industrial automation. Where closed-loop control systems is implemented for Better accuracy For such kind of measuring the Pulses coming from sensor are counted using many of the techniques such as use of microcontroller and display data using 7 -segment. But we are using here a CPLD instead of using Microcontroller because of CPLD having following advantages over microcontroller executes sequentially while CPLD works Concurrently as explain below CPLD runs at Higher Speed Than Microcontroller CPLD Executed no of instruction in single clock cycle while microcontroller execute a only one instruction for a single clock cycle CPLD is consist of no of PLD’s inside it which can be configured as per required application using VHDL language for microcontroller modules are fixed CPLD provides Flexibility of hardware reconfiguration Low power consumption Real Time performance