Contec DIO-32DM2-PE User Manual page 41

3. External Connection
Eternal start signal (EXTSTART0/EXTSTART1)
These input signals start bus mastering with an external signal. The signal level is LVTTL and you
can select and enable the rising or falling edge with the software. In order to detect the signal edge, a
high- and low-level hold time of 50ns is needed at minimum.
EXTSTART0
EXTSTSRT1
tHIH
tHIH : High level hold time 50ns (Min.)
tHIL : Low level hold time 50ns (Min.)
Figure 3.7. External start signal
External stop signal (EXTSTOP0/EXTSTOP1)
These input signals stop bus mastering with an external signal. The signal is LVTTL level and you can
select and enable the rising or falling edge with the software. In order to detect the signal edge, a high-
and low-level hold time of 50ns is needed at minimum.
Handshake Signal (EXTREQ0/EXTACK0/ EXTREQ1/EXTACK1)
These signals handshake with external devices. The signal is LVTTL level and controlled with
negative logic.
Input
EXTRAQ0 (In)
tREQIL
DATA (In)
EXTACK0 (Out)
tREQIL : EXTREQ0 low width 50ns (Min.)
tACKOL : EXTACK0 low width 100ns
tHSIN : Handshaking time 100ns (Min.)
Figure 3.8. Handshake Signals at the Time of Input
34
tHIL tHIH
(1)
Valid
Invalid
(2) (3)
tHSIN
tACKOL
DIO-32DM2-PE