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SLG46140
12.0 Combination Function Macrocells
The SLG46140 has eight combination function macrocells that can serve more than one logic or timing function. In each case,
they can serve as a Look Up Table (LUT), or as another logic or timing function. See the list below for the functions that can be
implemented in these macrocells:
•
Two macrocells that can serve as either 2-bit LUTs or as D Flip Flops
•
Two macrocells that can serve as either 3-bit LUTs or as D Flip Flops
•
One macrocell that can serve as either 3-bit LUT or as Pipe Delay
•
One macrocell that can serve as either 3-bit LUT or as 8-Bit Counter / Delay
•
One macrocell that can serve as either 4-bit LUT or 16-bit Pattern Generator
•
One macrocell that can serve as either 4-bit LUT or as 14-Bit Counter / Delay
Inputs/Outputs for the eight combination function macrocells are configured from the connection matrix with specific logic functions
being defined by the state of NVM bits.
When used as a LUT to implement combinatorial logic functions, the outputs of the LUTs can be configured to any user defined
function, including the following standard digital logic devices (AND, NAND, OR, NOR, XOR, XNOR).
When used as a D Flip Flop / Latch, the source and destination of the inputs and outputs for the DFF/Latches are configured from
the connection matrix. All DFF/Latch macrocells have user selection for initial state, and all have the option to connect both the
Q and Q Bar outputs to the connection matrix. The macrocells DFF2 and DFF3 have an additional input from the matrix that can
serve as a nSet or nReset function to the macrocell.
The operation of the D Flip-Flop and Latch will follow the functional descriptions below:
DFF: CLK is rising edge triggered, then Q = D; otherwise Q will not change.
Latch: when CLK is Low, then Q = D; otherwise Q remains its previous value (input D has no effect on the output, when CLK is
High).
12.1 2-Bit LUT or D Flip Flop Macrocells
There are two macrocells that can serve as either 2-bit LUTs or as D Flip Flops. When used to implement LUT functions, the 2-bit
LUTs each take in two input signals from the connection matrix and produce a single output, which goes back into the connection
matrix. When used to implement D Flip Flop function, the two input signals from the connection matrix go to the data (D) and clock
(CLK) inputs for the Flip Flop, with the output going back to the connection matrix.