Table A-1. Maximum Average Transfer Rates For The Pc-Dio-24 - National Instruments PC-DIO-24 User Manual

Specifications
Physical
Dimensions .................................................................. 17.5 by 9.9 cm (6.9 in. by 3.9 in.)
I/O connector............................................................... 50-pin male ribbon-cable connector
Power Requirement (from PC I/O Channel)
Typ power ................................................................... 0.10 A at 5 VDC ( 10%)
Max power .................................................................. 0.16 A at 5 VDC ( 10%)
Transfer Rates
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

Bus
AT (ISA16)
Assembly language code:
mov cx, 64
mov dx, 0180h
loop:
lodsb
out dx, al
add dx, 0014h
in al, dx
sub dx, 0014h
dec cx
jnz short loop
C code:
address = 0x0180;
ireg1address = address + 0x0014;
for (i = 0; i < 64; i++) {
outp(address, *data++);
inp(ireg1address);
}
PC-DIO-24 User Manual
CPU CPU Speed
486DX4 100 MHz
; Count out 64 transfers
; The port to access
; Assume ds:si points to buffer of data
; Send the data
; Add offset to base address for Ireg1
; Dummy read from Ireg1
; Restore base address
; The previous four lines are not
; necessary for measuring transfer rates
; Decrement the loop counter
; See if we need to loop
/* The port address */
/* Loop 64 times */
/* Send data */
A-2
Assembly C
410 kbytes/s 330 kbytes/s
© National Instruments Corporation
Appendix A