Access PCI-DIO-24D(H) User Manual

 
The following program fragment in C language illustrates the foregoing: 
  
 

const BASE_ADDRESS 0x300; 

 

outportb(BASE_ADDRESS +3, 0x89);  /*This instruction sets the mode to Mode 0, ports A and 

B as output, and port C as input. Since bit D7 is high, the 
output buffers are set to tristate condition. See item b. 
above.*/ 

 outportb(BASE_ADDRESS,0); 
 outportb(BASE_ADDRESS+1,0); /*These instructions set the initial state of ports A and B 

to all zeroes. Port C is not set because it is configured as 
an input. See item c. above.*/  

 

outportb(BASE_ADDRESS +3, 0x09);  /*Enable the tristate output buffers by using the same 

control byte used to configure the PPI, but now set bit 
D7 low. See item d. above.*/ 

  
The following example in BASIC is provided as a guide to assist you in developing your working software. 
In this example, the card base address is 2D0 hex and the I/O lines of group 0 are to be setup as follows:  
  
 Port 

A 

 = 

Input 

 Port 

B 

 = 

Output 

 

Port C Hi 

= 

Input 

 

Port C Lo 

= 

Output 

  

The first step is to configure the control register. Configure bits of the control register as: 
 

D7 1 Active 

Mode 

Set 

D6 0 Mode 

0 

D5 0 Mode 

0 

D4  1  Port A = input 
D3  1  Port C Hi = input 
D2 0 Mode 

0 

D1  0  Port B = output 
D0  0  Port C Lo -= output 

 
This corresponds to 98 hex. If the card address is 2D0 hex, use the BASIC OUT command to write to the 
control register as follows: 
  
 10 

BASEADDR=&H2D0 

 20 

OUT 

BASEADDR+3,&H98 

  
To read the inputs at Port A and the upper nybble of Port C: 
  
 

30 

X=INP(BASEADDR)'Read Port A  

 40 

Y=INP(BASEADDR+2)/16'Read Port C Hi 

  
To set outputs high (1) at Port B and the lower nybble of Port C:  
  
 

50 

OUT BASEADDR+1,&HFF'Turn on all Port B bits 

 

60 

OUT BASEADDR+2,&HF'Turn on all bits of Port C lower nybble  

Manual PCI-DIO-24DH 

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