Rear Transition Module detection
It is important to detect which duple of rear boards are connected. Six pins are committed to this feature: three pins for the RTM Motherboard and three pins for the RTM Panel board.
Board Detection
The board detection works in the same way as VME64x Geographical Address pins, in which every pin is opened by default and grounded while asserted. In the Front Board the open pin is internally pulled up, so when the FPGA detects a low level it indicates that a certain pin was asserted.
The alive signal for the RTM Motherboard and RTM Panel boards is generated in the Front Board. Logically, the alive signal corresponds to the OR'ed value of the corresponding set of FPGA pins used in the Board Detection.
Board Classification Pins
Rear Transition Module Motherboard (RTMM)
RTMM2 | RTMM1 | RTMM0 | |
RTMMv1 | Open | Open | GND |
Reserved | Open | GND | Open |
Reserved | Open | GND | GND |
Reserved | GND | Open | Open |
Reserved | GND | Open | GND |
Reserved | GND | GND | Open |
Reserved | GND | GND | GND |
Rear Transition Module Panel (RTMP)
RTMP2 | RTMP1 | RTMP0 | |
Blocking | Open | Open | GND |
RS-485 | Open | GND | Open |
Reserved | Open | GND | GND |
Reserved | GND | Open | Open |
Reserved | GND | Open | GND |
Reserved | GND | GND | Open |
Reserved | GND | GND | GND |