The Mint Correlator Design

Figure 2 A block diagram of the digital correlator as viewed from the top of the board.

1. Viewed from the top side (component side), the board accepts 4 signals from the left through SMA jacks.
2. All four digitizers are clocked by a signal entering the board from the right through a fifth SMA. Various Control signals used to synchronize the digitizers are generated by the system control FPGA (bottom right corner), synchronized with the clock, and distributed along with the clock to the four digitzers. The clock and control signals are carried across the board from right to left by traces on the top side.
3. Upon each clock, each digitizer coverts its analog signal into digital form. Then the digitizer performs a 1:16 deserialization and provides a divided-by-16 clock with the parallel data.
4. The Clock/16 registers the digitized data on the correlator FPGA located at board center.
5. Communication between the correlator FPGA and external devices is accomplished through a 50-pin connector at top right. The FPGA is programmed by on-board proms or by an external device through the 50-pin connector. (The proms are programmed by an external device through the 50-pin.) Data from the digitizers to the FPGA and out the 50-pin is carried left-to right across the board by traces on the back side.
6. In addition to generating control signals to synchornize the digitizers, the system controller connects to the correlator FPGA through 36 generic IO lines routed along the botom of the board. These generic IOs facilitate feedback: the system control FPGA may adjust board operation based upon information from the correlator FPGA.
7. The system control FPGA communicates with external devices through a 50-pin connector at board bottom right. The control FPGA may be programmed with a prom or externally through the 50-pin in direct analogy with the correlator FPGA.
8. Power to the board enters through large plated holes at the top of the board. Seven different voltages and two different grounds must be provided. The board will consume power on the order of hundreds of watts.