AN1924 Motorola / Freescale Semiconductor, AN1924 Datasheet - Page 7

• Manufacturer Part Number: AN1924
• Description: AN1924 Interfacing Serial LCDs to a DSP56F805s SCI and Porting Code Using the Embedded SDK
• Manufacturer: Motorola / Freescale Semiconductor

4.3 Connecting the LCD+ to the DSP56F805
4.4 Software for the LCD+ and the DSP56F805
In AN1921/D, the LCD+ device was interfaced to one of the DSP56824’s SPI ports using the Maxim
MAX3100 UART chip’s bi-directional capability to convert data conveyed by an SPI port to an
RS-232 format. However, the DSP56F80x’s SCI port can be connected directly to an RS-232 device
using the TTL voltage option compatible with NetMedia’s LCD+, making additional hardware
unnecessary.
The LCD+ has a much faster processor and the ability to support baud rates up to 57600. It also
provides support for a 4x4 matrix keypad which allos user input, resulting in two-way communication
between the LCD+ and the DSP56F805.
The software is written in C and makes full use of the SCI support provided in the Embedded SDK.
Code Example 2
display.
}
/* Display some numbers on display */
nanosleep(&FiveSeconds, NULL);
write( SciFD, NewScr, 1 );
for ( I=0; I < 29; I++ )
{
}
nanosleep(&FiveSeconds, NULL);
write( SciFD, NewScr, 1 );
temp = ’A’;
for ( I=0; I<26; I++ )
{
}
temp = ’a’;
for ( I=0; I<26; I++ )
{
}
nanosleep(&FiveSeconds, NULL);
sprintf(astring, "%d ", I );
write (SciFD, astring, strlen(astring));
sprintf( astring, "%c", temp++);
write (SciFD, astring, strlen(astring) );
sprintf( astring, "%c", temp++);
write (SciFD, astring, strlen(astring) );
demonstrates the interface between the DSP56F805 and NetMedia’s LCD+ serial
Interfacing LCDs and Porting Code
/* Wait five seconds */
/* Wipe clean LCD’s Display */
/* Write some numbers to LCD */
/* Wipe clean LCD’s Display */
/* Write capital letters to LCD */
/* Write small letters to LCD */
/* Wait five seconds */
/* Wait five seconds
Interfacing the LCDs to the DSP56F805
*/
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