Hi Mr. SPI
I think it will not be possible to create a SPI - Interface direct at LPT with your speed requirements - if I understand your timing right.
In general the clk-speed depends on OS ( Win9x is faster then NT, W2k, XP because of not using accesshw); and the CPU-speed.
Additionally I could speed-up aplications by using PCI-add-on cards instead of LPT on motherboard and creating an .exe-file for NT, W2K....
Find attached a simple vi, that sends Data to LPTx.
This can be used on your machine - take a look with a scope to clk-line and see how fast your PC is.
explanation of scope-picture in Diagram:
the Reference channels R1 + R2 are added in order to
show the different timing for .exe-file, created on
different OS.
Possibilities to overc
ome your problem:
- use a (buffered) I/O - board
- in case you have a Pattern Generator - load Data to
into this flexible machine
- take a MicroController and create an I/O program that
handles the Data-Transfer in your required speed (I
did this with - of course- ATMEL-µC (here the serial
port might be also a good choice)
hope this is not too much........
regards
wha
