EDE300 View Datasheet(PDF) - Unspecified
Part Name
Description
Manufacturer
EDE300 Datasheet PDF : 9 Pages
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Making use of the Dir/ Latch pin, the EDE300 can simultaneously latch data from a PC/ Stamp and
transmit data to the PC/ Stamp. The host PC/ Stamp would simply send a "1" command followed by
an output data byte, and then send a "2" command to tell the EDE300 to transmit data back. This
arrangement is shown in Figure Four below. The Dir/ Latch pin causes a data receive request to be
latched onto the '373, and a data transmit request to read from the '245. Note: use of the '245 may
in some circumstances cause brief glitches on the '373 outputs. We recommend this arrangement
only for output devices in which a small (0 to 25 ns) output glitch would be acceptable (eg. LED's,
relay control, etc.).
Figure Four: Simultaneous Bi-directional Host-Control Mode Arrangement
The following code, written in 'Turbo C', illustrates one method for using the EDE300 in bi-
directional mode:
#include <stdio.h>
char value;
/* main loop data variable */
send (char x)
{
while ((inportb(0x3FD) & 0x20) == 0);
outportb(0x3F8,0x31);
while ((inportb(0x3FD) & 0x20) == 0);
outportb(0x3F8,x);
}
/* write 'x' to EDE300 */
/* hold until transmitter is ready */
/* select 'receive byte' on EDE300 */
/* hold until transmitter is ready */
/* write 'x' to EDE300 */
COPYRIGHT © 1996 E-Lab Digital Engineering, Inc. All Rights Reserved. Page # 5
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