SLAAEO3 September   2024 MSPM0L2227 , MSPM0L2228

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction: MSPM0 and LCD End Applications
  5. 2MSPM0 LCD Portfolio
  6. 3Segmented LCD Operation
    1. 3.1 LCD Structure (Simplified)
    2. 3.2 LCD Drive Basics
  7. 4MSPM0 LCD Features
    1. 4.1 Muxing
      1. 4.1.1 Muxing Example
    2. 4.2 Voltage Generation
      1. 4.2.1 Charge Pump
      2. 4.2.2 Contrast Control
    3. 4.3 LCD Clocking
    4. 4.4 LCD Memory and Blinking Mode
      1. 4.4.1 LCD Memory Organization
      2. 4.4.2 Blinking
    5. 4.5 LCD Output Pin Configuration
    6. 4.6 Low Power Mode Feature
  8. 5LCD Layout and Software Considerations
    1. 5.1 LCD Layout Tips
      1. 5.1.1 Hardware-Driven Layout
      2. 5.1.2 Software-Driven Layout
      3. 5.1.3 General Layout Rules
    2. 5.2 LCD Software Tips
      1. 5.2.1 Create a Look-up Table
      2. 5.2.2 Use of #defines
      3. 5.2.3 Efficient Clearing of the LCD Memory
      4. 5.2.4 Double-buffering of the Display Buffer Using Dual Display Memory
  9. 6Additional Resources

Efficient Clearing of the LCD Memory

LCD modules support clearing the LCD memory using a single bit. The LCDCLRM (clears LCDM memory) or LCDCLRBM (clears LCDBM memory) bit is able to clear the entire LCD memory with a single instruction – all LCD display memory registers are cleared at the next frame boundary when LCDCLRM is set. After the memory registers are cleared, LCDCLRM is reset, so LCDCLRM is polled to see when the clear is completed. LCDCLRBM performs the same function and acts in the same way, however LCDCLRBM clears the blinking memory registers.

The clearing functionality is useful for efficiently clearing the whole screen and all memory registers. Therefore, preparation for updating the whole display as code must write only to memory registers that are used in the new display data, instead of also having to manually clear other registers for unused segments.