// Pre-add/subtract select with Dynamic control
// dynpreaddmultadd.v
module dynpreaddmultadd # (parameter SIZEIN = 16)
(
input clk, ce, rst, subadd,
input signed [SIZEIN-1:0] a, b, c, d,
output signed [2*SIZEIN:0] dynpreaddmultadd_out
);
// Declare registers for intermediate values
reg signed [SIZEIN-1:0] a_reg, b_reg, c_reg;
reg signed [SIZEIN:0] add_reg;
reg signed [2*SIZEIN:0] d_reg, m_reg, p_reg;
always @(posedge clk)
begin
if (rst)
begin
a_reg <= 0;
b_reg <= 0;
c_reg <= 0;
d_reg <= 0;
add_reg <= 0;
m_reg <= 0;
p_reg <= 0;
end
else if (ce)
begin
a_reg <= a;
b_reg <= b;
c_reg <= c;
d_reg <= d;
if (subadd)
add_reg <= a_reg - b_reg;
else
add_reg <= a_reg + b_reg;
m_reg <= add_reg * c_reg;
p_reg <= m_reg + d_reg;
end
end
// Output accumulation result
assign dynpreaddmultadd_out = p_reg;
endmodule // dynpreaddmultadd