add_sub_lag.tdf

一个四位二进制加/减运算器。 要求：当控制端G＝0时做加运算

--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 8.1 cbx_cycloneii 2008:05:19:10:57:37:SJ cbx_lpm_add_sub 2008:05:19:10:49:01:SJ cbx_mgl 2008:08:08:15:16:18:SJ cbx_stratix 2008:08:05:17:10:23:SJ cbx_stratixii 2008:08:07:13:54:47:SJ  VERSION_END


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FUNCTION cyclone_lcell (aclr, aload, cin, clk, dataa, datab, datac, datad, ena, inverta, regcascin, sclr, sload)
WITH ( cin0_used, cin1_used, cin_used, lut_mask, operation_mode, output_mode, power_up, register_cascade_mode, sum_lutc_input, synch_mode, x_on_violation)
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[3..0].cin = ( add_sub_cella[2..0].cout, strx_lcell1.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