23
3�7 Synchronizing Multiple Modules
The PCIe-69814 provides a dedicated connector as system synchronization interface,
enabling multiple module synchronization. As shown, bi-directional SSI I/Os provides a
flexible connection between modules, allowing one SSI master PCIe-69814 to output SSI
signals to other slave modules. For more accurate synchronization between modules,
external sampling clock or external reference clock should be applied.
The table summarizes SSI functionalities.
Different signals cannot be routed onto the same trigger bus line.
SSI Timing Signal
Function
SSI Trig
Input/output trigger signal through SSI
All SSI signals are routed to the 16-pin connector from FPGA, enabling multi-module
synchronization. ACL-eSSI-2/ ACLeSSI-3/ACL-eSSI-4 cables can be used to synchronize 2, 3,
or 4 modules.
Signal
Direction
Descr�
Pin
SSI Trig
Input/Output
Trigger signal through SSI
1, 9, 11, 13, 15
GND
Ground
2, 4, 6, 8, 10, 12,14,16
Reserved
Input/Output
Reserved for future use
3, 5,7
Table 3-5: SSI Signal Location and Pin Definition