Giving external input to Triple Speed Ethernet

Hi,

To generate PRBS packet, LFSR5 is used for 32 bits

but I didn't understand the statement

next_value <= ((((next_value << 5) & 32'hFFFFFFE0) | ((next_value >> 27) & 32'h0000001F)) + 32'h33557799);

in this program:

begin

if(go_bit & !running_bit)

begin

next_value <= initial_value;

end

else if(((state == DATA_STATE) || (state == EOP_STATE)) && aso_src0_valid && aso_src0_ready)

begin

next_value <= ((((next_value << 5) & 32'hFFFFFFE0) | ((next_value >> 27) & 32'h0000001F)) + 32'h33557799);

end

Theory seems to be clear from here

http://www1.verigy.com/cntrprod/groups/public/documents/webcontent/cnsmprod_020300.pdf

but not the program.

could anybody please explain little bit?