79 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * leds.c -- control the led's on a Motorola mc68ec0x0 board.
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|  *
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|  * Copyright (c) 1995 Cygnus Support
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|  *
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|  * The authors hereby grant permission to use, copy, modify, distribute,
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|  * and license this software and its documentation for any purpose, provided
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|  * that existing copyright notices are retained in all copies and that this
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|  * notice is included verbatim in any distributions. No written agreement,
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|  * license, or royalty fee is required for any of the authorized uses.
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|  * Modifications to this software may be copyrighted by their authors
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|  * and need not follow the licensing terms described here, provided that
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|  * the new terms are clearly indicated on the first page of each file where
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|  * they apply.
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|  */
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| #include "leds.h"
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| 
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| /*
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|  * led_putnum -- print a hex number on the LED. the value of num must be a char with
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|  *              the ascii value. ie... number 0 is '0', a is 'a', ' ' (null) clears
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|  *		the led display.
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|  *		Setting the bit to 0 turns it on, 1 turns it off.
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|  * 		the LED's are controlled by setting the right bit mask in the base
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|  * 		address. 
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|  *		The bits are:
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|  *			[d.p | g | f | e | d | c | b | a ] is the byte.
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|  *
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|  *		The locations are:
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|  *		
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|  *			 a
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|  *		       -----
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|  *		    f |     | b
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|  *		      |  g  |
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|  *		       -----
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|  *                    |     |
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|  *                  e |     | c
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|  *                     -----
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|  *                       d                . d.p (decimal point)
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|  */
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| void
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| led_putnum ( num )
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| char num;
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| {
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|     static unsigned char *leds = (unsigned char *)LED_ADDR;
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|     static unsigned char num_bits [18] = {
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|       0xff,						/* clear all */
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|       0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x98, /* numbers 0-9 */
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|       0x98, 0x20, 0x3, 0x27, 0x21, 0x4, 0xe 		/* letters a-f */
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|     };
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| 
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|     if (num >= '0' && num <= '9')
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|       num = (num - '0') + 1;
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| 
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|     if (num >= 'a' && num <= 'f')
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|       num = (num - 'a') + 12;
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| 
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|     if (num == ' ')
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|       num = 0;
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| 
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|     *leds = num_bits[num];
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| }
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| 
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| /*
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|  * zylons -- draw a rotating pattern. NOTE: this function never returns.
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|  */
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| void
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| zylons()
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| {
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|   unsigned char *leds 	= (unsigned char *)LED_ADDR;
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|   unsigned char curled = 0xfe;
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| 
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|   while (1)
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|     {
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|       *leds = curled;
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|       curled = (curled >> 1) | (curled << 7);
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|       delay ( 200 );
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|     }
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| }
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