a_dpfifo_ihi.tdf

Altera FPGA CPLD设计高级篇电子书籍

--a_dpfifo ALLOW_RWCYCLE_WHEN_FULL=OFF DEVICE_FAMILY=Stratix LPM_NUMWORDS=8192 LPM_SHOWAHEAD=OFF lpm_width=8 OVERFLOW_CHECKING=ON UNDERFLOW_CHECKING=ON clock data empty full q rreq sclr usedw wreq
--VERSION_BEGIN 4.0 cbx_altdpram 2003:08:18:15:59:18:SJ cbx_altsyncram 2003:12:02:15:28:30:SJ cbx_fifo_common 2003:08:19:18:07:00:SJ cbx_lpm_compare 2003:09:10:10:27:44:SJ cbx_lpm_counter 2003:12:16:17:25:44:SJ cbx_lpm_decode 2003:03:25:17:43:04:SJ cbx_lpm_mux 2003:10:21:14:09:22:SJ cbx_mgl 2004:01:13:14:00:54:SJ cbx_scfifo 2003:11:25:13:14:44:SJ cbx_stratix 2003:12:15:10:23:28:SJ cbx_stratixii 2003:11:06:16:12:54:SJ cbx_util 2003:12:05:10:31:30:SJ  VERSION_END


--  Copyright (C) 1988-2004 Altera Corporation
--  Any  megafunction  design,  and related netlist (encrypted  or  decrypted),
--  support information,  device programming or simulation file,  and any other
--  associated  documentation or information  provided by  Altera  or a partner
--  under  Altera's   Megafunction   Partnership   Program  may  be  used  only
--  to program  PLD  devices (but not masked  PLD  devices) from  Altera.   Any
--  other  use  of such  megafunction  design,  netlist,  support  information,
--  device programming or simulation file,  or any other  related documentation
--  or information  is prohibited  for  any  other purpose,  including, but not
--  limited to  modification,  reverse engineering,  de-compiling, or use  with
--  any other  silicon devices,  unless such use is  explicitly  licensed under
--  a separate agreement with  Altera  or a megafunction partner.  Title to the
--  intellectual property,  including patents,  copyrights,  trademarks,  trade
--  secrets,  or maskworks,  embodied in any such megafunction design, netlist,
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FUNCTION a_fefifo_n4f (aclr, clock, rreq, sclr, wreq)
RETURNS ( empty, full, usedw_out[12..0]);
FUNCTION dpram_btj (data[7..0], inclock, outclock, outclocken, rdaddress[12..0], wraddress[12..0], wren)
RETURNS ( q[7..0]);
FUNCTION lpm_counter (aclr, aload, aset, cin, clk_en, clock, cnt_en, data[LPM_WIDTH-1..0], sclr, sload, sset, updown)
WITH ( 	lpm_avalue,	lpm_direction,	lpm_modulus,	lpm_svalue,	lpm_width) 
RETURNS ( cout, eq[15..0], q[LPM_WIDTH-1..0]);

--synthesis_resources = lpm_counter 3 lut 12 ram_bits (M4K) 65536 
SUBDESIGN a_dpfifo_ihi
( 
	clock	:	input;
	data[7..0]	:	input;
	empty	:	output;
	full	:	output;
	q[7..0]	:	output;
	rreq	:	input;
	sclr	:	input;
	usedw[12..0]	:	output;
	wreq	:	input;
) 
VARIABLE 
	fifo_state : a_fefifo_n4f;
	FIFOram : dpram_btj;
	rd_ptr_count : lpm_counter
		WITH (
			lpm_direction = "UP",
			lpm_width = 13
		);
	wr_ptr : lpm_counter
		WITH (
			lpm_direction = "UP",
			lpm_width = 13
		);
	aclr	: NODE;
	rd_ptr[12..0]	: WIRE;
	valid_rreq	: WIRE;
	valid_wreq	: WIRE;

BEGIN 
	fifo_state.aclr = aclr;
	fifo_state.clock = clock;
	fifo_state.rreq = rreq;
	fifo_state.sclr = sclr;
	fifo_state.wreq = wreq;
	FIFOram.data[] = data[];
	FIFOram.inclock = clock;
	FIFOram.outclock = clock;
	FIFOram.outclocken = (valid_rreq # sclr);
	FIFOram.rdaddress[] = ((! sclr) & rd_ptr[]);
	FIFOram.wraddress[] = wr_ptr.q[];
	FIFOram.wren = valid_wreq;
	rd_ptr_count.aclr = aclr;
	rd_ptr_count.clock = clock;
	rd_ptr_count.cnt_en = valid_rreq;
	rd_ptr_count.sclr = sclr;
	wr_ptr.aclr = aclr;
	wr_ptr.clock = clock;
	wr_ptr.cnt_en = valid_wreq;
	wr_ptr.sclr = sclr;
	aclr = GND;
	empty = fifo_state.empty;
	full = fifo_state.full;
	q[] = FIFOram.q[];
	rd_ptr[] = rd_ptr_count.q[];
	usedw[] = fifo_state.usedw_out[];
	valid_rreq = (rreq & (! fifo_state.empty));
	valid_wreq = (wreq & (! fifo_state.full));
END;
--VALID FILE