// LLRF history buffers for test submodule
// Larry Doolittle, LBNL, March 2003
// See history2k.v for its care and feeding
// 2K x 14 buffer, programmable averaging

`timescale 1ns / 1ns

module hist4(
	clk40, in_data, trace_address, write_enable, clear,
	clk_host, host_dout, host_addr);
input  clk40;
input  [11:0] in_data;
input  [10:0] trace_address;
input  write_enable, clear;
input  clk_host;
output [13:0] host_dout;
input  [11:0] host_addr;

wire [13:0] recirc;
// convert from offset binary, and then sign extend from 12 to 14 bits
wire [13:0] extend_in = {{3{~in_data[11]}},in_data[10:0]};
wire [13:0] sum = clear ? in_data : (in_data+recirc);

ramdp2048x14 trace1(
	.ADDRA(trace_address),
	.RSTA(1'b0),
	.ENA(1'b1),
	.WEA(write_enable),
	.CLKA(clk40),
	.DIA(sum),
	//.DOA(void), // read from host
	.ADDRB(host_addr[10:0]),
	.RSTB(1'b0),
	.ENB(1'b1),
	.WEB(1'b0), // host write not allowed
	.CLKB(clk_host),
	.DIB(14'b000000000000), // not used
	.DOB(host_dout));

// four-deep FIFO
srl16x14e fifo(
	.Q(recirc), .A0(1'b1), .A1(1'b1), .A2(1'b0), .A3(1'b0),
	.CE(write_enable), .CLK(clk40), .D(sum));

endmodule