LCD

The LCD character display can be used in three different ways:

• Output ASCII characters over a simple LCD controller.
• Output binary values in HEX representation (max. 128 bit).
• Access the display directly over the I²C interface.

Each colour of the background light is controlled by a 16 bit PWM controller.

The binary interface can be used to display binary values in HEX representation. A maximum of 128 bits can be displayed.

The code snippet bellow shows how to use the ASCII interface of the LCD.

#include "reg_ctboard.h"
 
CT_LCD->BIN.BYTE.B7_0 = (uint8_t) data_byte;           /* Write byte of data to LCD. */
CT_LCD->BIN.HWORD.B31_16 = (uint16_t) data_halfword;   /* Write halfword of data to LCD. */
CT_LCD->BIN.WORD.B63_32 = (uint32_t) data_word;        /* Write word of data to LCD. */
CT_LCD->BIN.DWORD = (uint64_t) data_doubleword;        /* Write doubleword of data to LCD. */

ADDR_LCD_BIN    EQU      0x60000320
 
                LDR      r0, =ADDR_LCD_BIN
                STRB     r1, [r0, #0]                  ; Write byte of data to LCD.
                STRH     r1, [r0, #2]                  ; Write halfword of data to LCD.
                STR      r1, [r0, #4]                  ; Write word of data to LCD.
                STRD     r1, [r0, #0]                  ; Write doubleword of data to LCD.

The Registers are read / write.

Each colour of the background light is controlled by a 16 bit PWM generator.
The brightness can be regulated from 0x0000 (0% / off) to 0xffff (100%). To adapt the brightness curve to the human eye a adadption to a logarithmic scale has to be done manually.

The code snippet bellow shows how to set the background light on the LCD.

#include "reg_ctboard.h"
 
CT_LCD->BG.RED = (uint16_t) data_halfword;        /* Set PWM value for red background light. */
CT_LCD->BG.GREEN = (uint16_t) data_halfword;      /* Set PWM value for green background light. */
CT_LCD->BG.BLUE = (uint16_t) data_halfword;       /* Set PWM value for blue background light. */

ADDR_LCD_BG     EQU      0x60000304
 
                LDR      r0, =ADDR_LCD_BG
                STRH     r1, [r0, #0]             ; Set PWM value for red background light.
                STRH     r1, [r0, #2]             ; Set PWM value for green background light.
                STRH     r1, [r0, #4]             ; Set PWM value for blue background light.

The Registers are read / write.