void LCD_byte (unsigned char x)
{
// The accumulator in the C8051Fxxx is bit addressable!
ACC=x; //Send high nible
LCD_D7=ACC_7;
LCD_D6=ACC_6;
LCD_D5=ACC_5;
LCD_D4=ACC_4;
LCD_pulse();
Timer3us(40);
ACC=x; //Send low nible
LCD_D7=ACC_3;
LCD_D6=ACC_2;
LCD_D5=ACC_1;
LCD_D4=ACC_0;
LCD_pulse();
}
/**
* @brief Send a byte to the LCD using a 4-bit wide interface.
*
* @param C is the character to be sent to the LCD.
*
* @return void
*
* @note
*
* - When assigning a char to a single bit the MICROCHIP C18 compiler assigns
* the the character's LSB to the single bit. This is convenient in this
* function as it allows the individual bits to be assigned using a series of
* shift left commands.
*
* - This function assumes other background function will use the data I/O.
* Consequently, it starts by configuring the data lines as outputs.
*
*/
static void LCD_w_byte (char C) {
LCD_D0_DIRECTION = OUTPUT;
LCD_D1_DIRECTION = OUTPUT;
LCD_D2_DIRECTION = OUTPUT;
LCD_D3_DIRECTION = OUTPUT;
LCD_D0_PIN = C >> 4; // send the upper nibble
LCD_D1_PIN = C >> 5;
LCD_D2_PIN = C >> 6;
LCD_D3_PIN = C >> 7;
LCD_pulse();
LCD_D0_PIN = C & 0x01; // send the lower nibble
LCD_D1_PIN = C >> 1;
LCD_D2_PIN = C >> 2;
LCD_D3_PIN = C >> 3;
LCD_pulse();
// LCD_D3_DIRECTION = INPUT; /**@todo WHY? */
// delay_ISR_ticks(2);
}
