LEONI eol 1x2 - Parallel Interface Control

REV 07a / 01_ 2012
9
Parallel Interface
- Switch can only receive data, not transmit
- Switch can be programmed either with or without a chipselection signal (strobe)
- Interface operates with standard TTL levels (see LEONI Manual)
- Case1: without strobe
After detecting a new switching state (binary code) at the data input port, the switches moves
to the corresponding channel after time delay t
1.
In order to avoid problems this code must be
kept constant for this period.
t
1
> 40µsek
- Case 2: with Strobe (standard interface operation)
By a HIGH– LOW slope, data at the parallel interface ports are transferred into the switch and
stored there (latch). The LOW level for the strobe input must be constant for a time period t
1
.
Before the HIGH – LOW slope the strobe signal has to be at HIGH level at least for a time
duration t
2
. Switching occures after a duration t
3
.
t
1
>45µsek
t
2
>45µsek
t
3
t
1
+20µsek
CH n
CH m
DATA0..3:
t
1
Mechanical
Switching process
CH m
DATA0..3:
t
1
Mechanical
switching
Strobe:
t
2
t
3