driver de exibição lcd ic
The display driver IC is the main part of the display imaging system. It integrates components such as resistors, regulators, comparators and power transistors, including LCD modules and display subsystems. It is responsible for driving the display and controlling the driving current. It is divided into static There are two methods of driving and dynamic driving.
Features
Internal self-built 256khzrc oscillator, external 32. 768khz crystal or 256khz frequency input, internal 324bit display ram selectable 1/2 or 1 /3 bias, and 1/2, 1 /3 or 1 /4 3 terminal serial interface The duty cycle LCD display the built-in LCD drive signal source. The internal time reference frequency can be controlled by instructions. The drive signal frequency of the buzzer can be selected 2khz or 4khz. Data mode and command mode instructions have shutdown instructions to reduce power consumption. r/w address automatically accumulates internal time Base generator and wdt watchdog timer 3 data access modes. Time base or wdt overflow output. The vlcd pin is used to adjust the lcd operating voltage
composição ic
(1) The ram static display (ram) structure is 324 bits, which stores the displayed data. The content of ram is directly mapped to the content of the lcd drive. The data in ram can be accessed by read, write and read—modify—write commands. (2) System oscillator cms1 621 The system clock is used to generate the clock of the time base/wdt circuit, the lcd drive clock and the buzzer frequency. The clock can come from the on-chip rc oscillator (256khz), crystal oscillator (32.768khz) or an external 256khz clock set by s/w. (3) Time base and watchdog timer The time base generator is composed of an 8-level up counter, which is used to design and produce an accurate time base. The watchdog timer (wdt) is composed of an 8-level time base generator and a 2-level up counter. It is used to stop the main controller or Other subsystems. (4) Buzzer output A simple buzzer oscillator is provided in cms1 621. The buzzer oscillator can provide a pair of buzzer drive signals bz and __bz to generate a simple buzzer. Execute the tone 4k and tone 2k commands to generate two beep frequencies. The tone 4k and tone 2k commands set the beep frequencies to 4khz and 2khz respectively. The beep drive signal can be turned on or off by calling the tone on or tone off commands. (5) The lcd driver cms1 621 is a 128 (324) dot matrix lcd driver, which can drive 1/2 or 1/3 bias, 2, 3 or 4 com terminal lcd displays. This feature makes cms1621 Suitable for a variety of LCD displays. (6) The command format cms1621 can be set by s/w. There are two modes for the command for setting cms1621 and transmitting LCD display data, namely command mode and data mode. The setting of cms1621 is called command mode, where id is 100, which is composed of system setting command, system frequency selection command, lcd structure command, buzzer frequency selection command and operation command. (7) Interface cms1 621 has 4 lines that need interface. __cs Initialize the serial interface circuit and connect the communication terminal between the main controller and. When __cs is 1, the data and commands between the main controller and cms1 621 are prohibited and initialized.
