Achronix Speedster22i User Macro Guide - Manual (Page 101)

Speedster Macro Cell Library Achronix Semiconductor Proprietary PAGE 84
Chapter 4 – Lookup Table (LUT) Functions
LUT4
Four Input Lookup Table
din0
LUT4 q
din1
din2
din3
Figure 4-1: Logic Symbol
LUT4 implements a four‐input lookup table with data inputs (din0 ‐ din3) and data output (q),
whose function is defined by the sixteen‐bit lut_function parameter. The LUT4 is treated as a
black‐box by the synthesis tools. The user may instantiate this block to define specific
structures of logic functions.
Pins
Table 4-1: Pin Descriptions
Name Type Description
din0 - din3 Data inputs.
q
Data output. The value on dout is the bit of the lut_function parameter
indexed by the inputs {din3,din2,din1,din0}.
Parameters
Table 4-2: Parameters
Parameter Defined Values Default Value
lut_function 16’h0
lut_function
The lut_function parameter defines the value on the q output of the LUT4 as detailed in Table
4‐3: Function Table . The default value of the lut_function parameter is 16’h0.
input
output
16-bit hexadecimal value