par_gen.tdf

《FPGA嵌入式应用系统开发典型实例》-书的光盘资料

TITLE "Parameterized Parity Checker"; 


%//////////////////
// INCLUDE FILES //
//////////////////%

INCLUDE "lpm_dff.inc";
INCLUDE "lpm_add_sub.inc";
INCLUDE "lpm_compare.inc";
INCLUDE "lpm_constant.inc";

%////////////////////////////
// USER-DEFINED PARAMETERS //
////////////////////////////%

PARAMETERS
(
 WIDTH=1
);

%/////////////////////
// INPUTS & OUTPUTS //
/////////////////////%

SUBDESIGN Par_Gen
(
 D[WIDTH-1..0]		: INPUT;
 ODD/EVEN			: OUTPUT;
)

%/////////////////////////
// VARIABLE DEFINITIONS //
/////////////////////////%

VARIABLE
 OUT[WIDTH-1..0]	: NODE;


%//////////////////
// LOGIC SECTION //
//////////////////%

BEGIN

 ASSERT (WIDTH > 0)
 REPORT "Value of WIDTH parameter must be greater than 0"
 SEVERITY ERROR;

 OUT[0] = D[0];
 FOR i IN 1 TO WIDTH-1 GENERATE
  OUT[i] = OUT[i-1] $ D[i];
 END GENERATE;

 ODD/EVEN=OUT[WIDTH-1];

END;