4.0 Module Port Declerations
port_direction is declared as:
inputfor scalar or vector input ports.
outputfor scalar or vector output ports.
inoutfor scalar or vector bi-directional ports.
port_size is a range from
](most-significant-bit to least-significant-bit).
- The msb and lsb must be literal integers, integer parameters, or an expression that resolves to an integer constant.
- Either little-endian convention (the lsb is the smallest bit number) or big-endian convention (the lsb is the largest bit number) may be used.
- The maximum port size may be limited, but will be at least 256 bits.
3 scalar ports
output [7:0] result;
little endian convention
inout [0:15] data_bus;
big endian convention
input [15:12] addr;
msb:lsb may be any integer
parameter word = 32;
input [word-1:0] addr;
constant expressions may be used