Easy to modify LED light sequence circuit design without processor intervention

LED technology is increasingly being applied to our lives. For developers, LEDs or other device sequencers are implemented through a system-on-a-chip (SOC) platform to find a design requirement that reduces costs and reduces design complexity. More and more common. The SOC device integrates the microcontroller functions and various digital peripherals required for a complete LED subsystem on a single chip. This article describes a simple 8 LED light sequence circuit design based on the latest SOC technology. The most exciting part of this design is that the microprocessor does not need to intervene. Rather than using traditional passive digital peripherals interspersed with microcontroller processors, this design is based entirely on the intelligent distributed processing capabilities of SOC digital systems. This frees the central processor from managing the operation of the light sequence circuit, saving CPU resources and making the design more efficient.

This design method can be easily extended to other devices other than LEDs that need to be turned on or off in a specified order, such as sequence timers of different lengths and different modes. There are additional features in this design example:

· 7-bit counter (TC) terminal count

· Instruct the device to turn off the output

· 8-bit output for serial devices

· Clock input to the Verilog state machine

· Bus clock for 8-bit ALU (bit-slice) processor

The development tool used in this article is PSoC Creator, an integrated development environment for Cypress Semiconductor Programmable System-on-Chip (PSoC).

Schematic design

The first step in the design is to create a Verilog symbol to define the input, output, and bit width associated with it (see Figure 1). Once the upper Verilog model (schematic) has been created, it can be used to generate Verilog source files containing pin definitions in all modules. This step does not require the development of functional Verilog code.

Figure 1: Verilog symbol.

The Verilog symbol you just created can now be placed into a high-level schematic design. Here, each input and output can be connected to a clock source, I/O pins, status and control registers, and so on. The high-level principle design of 8-LED lamp sequence circuit is shown in Figure 2.

Figure 2: Example of a high-level design.

Until now, the Verilog symbol has been created, placed in a high-level design, and connected to the device's I/O and clock. Verilog code can now be generated to perform certain functions, in this case the LEDs can be flashed. To manage the logical capabilities of the sequence, a simple data path can be introduced into the design.