add_sub_lag.tdf

布思基四乘法器实现,很好用,快来看,希望对大家有所帮助.

--lpm_add_sub CARRY_CHAIN="MANUAL" CARRY_CHAIN_LENGTH=48 DEVICE_FAMILY="Cyclone" LPM_REPRESENTATION="UNSIGNED" LPM_WIDTH=4 ONE_INPUT_IS_CONSTANT="NO" add_sub dataa datab result
--VERSION_BEGIN 5.0 cbx_cycloneii 2004:12:20:14:28:52:SJ cbx_lpm_add_sub 2005:04:12:13:30:42:SJ cbx_mgl 2005:05:19:13:51:58:SJ cbx_stratix 2005:11:01:14:36:46:SJ cbx_stratixii 2004:12:22:13:27:12:SJ  VERSION_END


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--  functions, and any output files any of the foregoing 
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--  without limitation, that your use is for the sole purpose of 
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FUNCTION cyclone_lcell (aclr, aload, cin, clk, dataa, datab, datac, datad, ena, inverta, regcascin, sclr, sload)
WITH ( 	cin_used,	lut_mask,	operation_mode,	output_mode,	register_cascade_mode,	sum_lutc_input,	synch_mode) 
RETURNS ( combout, cout, regout);

--synthesis_resources = lut 5 
SUBDESIGN add_sub_lag
( 
	add_sub	:	input;
	dataa[3..0]	:	input;
	datab[3..0]	:	input;
	result[3..0]	:	output;
) 
VARIABLE 
	add_sub_cella0 : cyclone_lcell
		WITH (
			cin_used = "true",
			lut_mask = "96E8",
			operation_mode = "arithmetic",
			sum_lutc_input = "cin"
		);
	add_sub_cella1 : cyclone_lcell
		WITH (
			cin_used = "true",
			lut_mask = "96E8",
			operation_mode = "arithmetic",
			sum_lutc_input = "cin"
		);
	add_sub_cella2 : cyclone_lcell
		WITH (
			cin_used = "true",
			lut_mask = "96E8",
			operation_mode = "arithmetic",
			sum_lutc_input = "cin"
		);
	add_sub_cella3 : cyclone_lcell
		WITH (
			cin_used = "true",
			lut_mask = "9696",
			operation_mode = "normal",
			sum_lutc_input = "cin"
		);
	strx_lcell1 : cyclone_lcell
		WITH (
			cin_used = "false",
			lut_mask = "00CC",
			operation_mode = "arithmetic"
		);

BEGIN 
	add_sub_cella[0].cin = strx_lcell1.cout;
	add_sub_cella[1].cin = add_sub_cella[0].cout;
	add_sub_cella[2].cin = add_sub_cella[1].cout;
	add_sub_cella[3].cin = add_sub_cella[2].cout;
	add_sub_cella[3..0].dataa = datab[];
	add_sub_cella[3..0].datab = dataa[];
	add_sub_cella[3..0].inverta = (! add_sub);
	strx_lcell1.dataa = B"0";
	strx_lcell1.datab = (! add_sub);
	strx_lcell1.inverta = (! add_sub);
	result[] = add_sub_cella[3..0].combout;
END;
--VALID FILE