Справочник Пользователя для National Instruments PC-DIO-24

Dimensions ..................................................................

 

17.5 by 9.9 cm (6.9 in. by 3.9 in.)

I/O connector...............................................................

 

50-pin male ribbon-cable connector

Typ power ...................................................................

 

0.10 A at 5 VDC (

±

10%)

Max power ..................................................................

 

0.16 A at 5 VDC (

±

10%)

The maximum average transfer rates for the PC-DIO-24 are shown as follows.  The code used to make the
measurements follows the table.  The assembly language code was assembled as inline assembly C code using
version 8.00 of the Microsoft Optimizing C Compiler.  The C code was compiled using version 8.00 of the
Microsoft Optimizing C Compiler.

Table A-1.  Maximum Average Transfer Rates for the PC-DIO-24

AT (ISA16)

486DX4

100 MHz

410 kbytes/s

330 kbytes/s

Assembly language code:

mov

cx, 64

; Count out 64 transfers

mov

dx, 0180h

; The port to access

loop:

lodsb

; Assume ds:si points to buffer of data

out

dx, al

; Send the data

add

dx, 0014h

; Add offset to base address for Ireg1

in

al, dx

; Dummy read from Ireg1

sub

dx, 0014h

; Restore base address
; The previous four lines are not
; necessary for measuring transfer rates

dec

cx

; Decrement the loop counter

jnz

short loop

; See if we need to loop

C code:

address = 0x0180;

/* The port address */

ireg1address = address + 0x0014;
for (i = 0; i < 64; i++) {

/* Loop 64 times */

outp(address, *data++);

/* Send data */

inp(ireg1address);

}