Interfacing MAX6952

This is a driver to interface MAX6952(5 x 7 dot-matrix LED display driver ) with PIC Micro. Compiled with CCS PICC

#define max_sdi PIN_C5
#define max_sdo PIN_C4
#define max_clk PIN_C3
#define max_cs  PIN_C2

const int8 user_font[120]= {0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C,
                            0x77,0x6B,0x5D,0x6B,0X77,
                            0x1C,0x22,0x7F,0x22,0x1C};
                                                        

#define config_addr 0x04
#define font_addr   0x05
#define test_addr   0x07
#define plane01_addr     0x20
#define plane02_addr     0x21
#define plane03_addr     0x22
#define plane04_addr     0x23
#define plane11_addr     0x40
#define plane12_addr     0x41
#define plane13_addr     0x42
#define plane14_addr     0x43

int8 config_byte;

void write_to_6952(int8 cmd,int8 data)
{
    int8 i;
    int16 ser_data;
    ser_data=make16(cmd,data);
    //shift_right(&ser_data,2,0);
    output_low(max_clk);
    output_low(max_cs);
    for(i=1;i<=16;++i)
    {
        output_bit(max_sdi,shift_left(&ser_data,2,0));
        output_high(max_clk);
        delay_us(10); 
       // if(i<16)       
            output_low(max_clk);
        //delay_us(6); 
    }
    output_high(max_cs);
    output_low(max_clk);
}   

void write_user_font()
{
    int8 j;
    write_to_6952(font_addr,0x80);
    for(j=0;j<120;j++)
    {
        write_to_6952(font_addr,user_font[j]);
    }    
}    
/*******************************************************************
if state=1,normal operation
if state=0,shutdown
if wrt=1,write to 6952,otherwise update the config_byte register
*******************************************************************/
void shutdown(int1 state, int1 wrt)
{
    if(state)
        config_byte |= 0x01;
    else
        config_byte &= 0xFE;
    if(wrt)
        write_to_6952(config_addr,config_byte);
}
/*******************************************************************
if state=1,enable blinking
if state=0,disable blinking
if wrt=1,write to 6952,otherwise update the config_byte register
*******************************************************************/
void blink_enable(int1 state,int1 wrt )
{
    if(state)
       config_byte |= 8;
    else
       config_byte &= 0xF7;
    if( wrt )
        write_to_6952(config_addr,config_byte);
}

/*************************************************************************
if state=1,put the display in test mode
if state=0,normal mode
Does not affect plane data - original display is restored when set 0.
**************************************************************************/
void display_test(int1 state )
{
     if(state)
        write_to_6952(test_addr,1);
     else
        write_to_6952(test_addr,0);
}