Silego GreenPAK SLG46140, Руководство пользователя

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SLG46140
12.3 3-Bit LUT or Pipe Delay Macrocell
There is one macrocell that can serve as either a 3-bit LUT or as a Pipe Delay.
When used to implement LUT functions, the 3-bit LUT take in three input signals from the connection matrix and produces a single
output, which goes back into the connection matrix.
When used as a pipe delay, there are three input signals from the matrix, Input (IN), Clock (CLK) and Reset (RST). The pipe delay
cell is built from 16 D Flip-Flop logic cells that provide the three delay options, two of which are user selectable. The DFF cells
are tied in series where the output (Q) of each delay cell goes to the next DFF cell. The first delay option (OUT2) is fixed at the
output of the first flip-flop stage. The other two outputs (OUT0 and OUT1) provide user selectable options for 1 – 16 stages of
delay There are delay output points for each set of the OUT0 and OUT1 outputs to a 4-input mux that is controlled by reg
<753:750> for OUT0 and reg <757:754> for OUT1. The 4-input mux is used to control the selection of the amount of delay.
The overall time of the delay is based on the clock used in the SLG46140 design. Each DFF cell has a time delay of the inverse
of the clock time (either external clock or the RC Oscillator within the SLG46140). The sum of the number of DFF cells used will
be the total time delay of the Pipe Delay logic cell.
Figure 44. 3-bit LUT6 or Pipe Delay
3-bit LUT6
OUT IN1
IN0
reg <757:750>
From Connection
Matrix Output <40>
From Connection
Matrix Output <41>
IN2
From Connection
Matrix Output <42>
16 Flip-Flops
IN
RST
CLK
From Connection
Matrix Output <42>
From Connection
Matrix Output <41>
From Connection
Matrix Output <40>
reg <757:754>
reg <753:750>
To Connection
Matrix Input<20>
To Connection
Matrix Input <19>
OUT1
OUT0
reg <758>
0
1
To Connection
Matrix Input <18>
OUT2
reg <759>
0
1