Products Mentioned

MAX7300 Production
The MAX7300 compact, serial-interfaced, I/O expansion peripheral provides microprocessors with up to 28 ports. Each port is individually user configurable...
Datasheet
MAX7300 on Analog.com

Associated Drivers

  • State Verified Answer
  • Replies 1 reply
  • Subscribers 81 subscribers
  • Views 271 views
  • Users 0 members are here
Options
Related 

        

            Post
             Go back to editing
        

    

    


    

    









		












	
	
			
	
			
		
	
	
		

		
MAX7300 Interrupt pin



		

			

									
					    KEA869
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Apr 15, 2024 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    I'm trying to use the P31 pin of the MAX7300 IO Expander as an interrupt output. According to the datasheet, by setting  D7=0 and D6 = 1 in the port configuration register, it automatically becomes an active-high interrupt output.
    (Port Configuration for P31, P30, P29, P28 => 0b01111111 - 930-P28 are inputs)
    

    However, it seemingly doesn't generate any interrupts upon triggering the other input pins. I've tried to measure it with oscilloscope multiple times, but no signal shows up
    (I've checked the oscilloscope settings many times), and when I check in code if the supposed bit is high (1), it doesn't work accordingly.
    

    Any tips on how to solve this, or is there any additional configurations I have to set for this function to work?
    

    Thank you in advance!
    
									
			                
    Thread Notes   
    
        
    
        
            
		
    

				
						
        

    
    Tags: 
                                            
                 interrupt
                
                                                    
                 firmware
                
                                                    
                 Display Driver Electronics
                
                                                    
                 Direct from Battery LED/GPIO Drivers
                
                                                    
                 expander
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                        
                                            
                
                
                                
                    Show More
            
    
    
    

		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

    • 
	
      



	
			
		
	



      
	
      
		
      
							
					
      
		
      
			
													0
							
			
				
									
							        
			
			
			
        
            
						
                            
            
            				
            
                on Apr 16, 2024 8:45 AM
            
            
					
        
	
        

		
		
        
					
        Hi,
        

        Note that the MAX7300 does not identify which specific port(s) caused the interrupt but provides an alert that one or more port levels have changed.
        

        Verify your settings for enabling P31 as Interrupt output. You should enable the transition detection control by setting D7=1 & D6=0 as shown.
        

                                  
        

        Once transition detection is enabled, the MAX7300 continuously compares the snapshot register against the changing states of P24 through P31. If a change on any of the monitored ports is detected, even for a short time (like a pulse), the INT status bit (transition detection mask register bit D7) is set. Port P31 (if enabled as INT output) also goes high. The INT output and INT status bit are not cleared if more changes occur or if the data pattern returns to its original snapshot condition.
        

        Please refer page No 11 and 16 refer: 3376.pdf (analog.com)
        

        

        To set the output level of a specific MAX7300 output you will either set the data bit to a 0 (output LOW) or a 1 (output HIGH). Table 5 will tell you which data bit is relevant to change the specified port or set of ports. 
        

         
        

        Also please note that, only Maxim ATE products are supported on Engineer Zone at this time. Over the next several months, you will see more Maxim products being supported in Engineer Zone. Please visit one of the technical support pages on our newly integrated website below for assistance with Maxim Integrated products.
        

        


        CN - https://support.analog.com/zh-CN/technical-support/ 
        

        JP - https://support.analog.com/ja-JP/technical-support/ 
        

        Thanks,
        Dharani S
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
						
						
				
				
		
		
        
			
		
        
	
        

        

        •