// BRAM Partial LUT for Morphic DSP
// Implements adaptive storage for pattern matching, weights, thresholds
// Target: Lattice iCE40 HX8K / ECP5
// Q16.16 fixed-point arithmetic

`timescale 1ns / 1ps

// ═══════════════════════════════════════════════════════════════════════════
// BRAM Partial LUT Module
// 1024-entry lookup table (10-bit address, 32-bit Q16.16 data)
// Supports runtime updates via write enable
// ═══════════════════════════════════════════════════════════════════════════
module bram_partial_lut (
    input  wire        clk,
    input  wire        we,           // Write enable
    input  wire [9:0]  addr,         // Address (1024 entries)
    input  wire [31:0] din,          // Data in (Q16.16)
    output reg  [31:0] dout          // Data out (Q16.16)
);
    // BRAM storage (1024 x 32-bit)
    reg [31:0] memory [0:1023];
    
    // Read/write operation
    always @(posedge clk) begin
        if (we) begin
            memory[addr] <= din;  // Write
        end
        dout <= memory[addr];      // Read (registered output)
    end
    
endmodule

// ═══════════════════════════════════════════════════════════════════════════
// BRAM Partial LUT with Morphic Scalar Integration
// Morphic scalar amplitudes drive BRAM updates
// ═══════════════════════════════════════════════════════════════════════════
module bram_partial_lut_morphic (
    input  wire        clk,
    input  wire        we,           // Write enable
    input  wire [9:0]  addr,         // Address
    input  wire [31:0] din,          // Data in
    output reg  [31:0] dout,         // Data out
    input  wire        update_enable, // Morphic scalar update enable
    input  signed [31:0] morphic_amplitude,  // Morphic scalar amplitude
    input  wire [9:0]  pattern_addr,  // Pattern address for matching
    output wire [31:0] pattern_match_threshold  // Pattern match threshold output
);
    // BRAM storage
    reg [31:0] memory [0:1023];
    
    // Morphic scalar update logic
    wire signed [31:0] updated_value;
    wire signed [31:0] current_value;
    wire signed [31:0] amplitude_scaled;
    
    // Scale morphic amplitude for BRAM update
    assign amplitude_scaled = morphic_amplitude >>> 8;  // Scale down by 256
    
    // Update calculation: new_value = old_value + scaled_amplitude
    assign updated_value = current_value + amplitude_scaled;
    
    // Read current value
    assign current_value = memory[addr];
    
    // Read/write operation
    always @(posedge clk) begin
        if (we) begin
            if (update_enable) begin
                memory[addr] <= updated_value;  // Morphic scalar update
            end else begin
                memory[addr] <= din;          // Direct write
            end
        end
        dout <= memory[addr];
    end
    
    // Pattern match threshold lookup
    assign pattern_match_threshold = memory[pattern_addr];
    
endmodule

// ═══════════════════════════════════════════════════════════════════════════
// BRAM Partial LUT for Pattern Matching
// Stores pattern matching thresholds (e.g., 72% match threshold)
// ═══════════════════════════════════════════════════════════════════════════
module bram_pattern_match_lut (
    input  wire        clk,
    input  wire        we,
    input  wire [9:0]  pattern_id,    // Pattern identifier
    input  wire [31:0] match_threshold,  // Match threshold (Q16.16, e.g., 0.72 = 72%)
    output reg  [31:0] current_threshold,
    output wire        match_detected  // Pattern match detected
);
    // BRAM storage for pattern thresholds
    reg [31:0] pattern_thresholds [0:1023];
    
    always @(posedge clk) begin
        if (we) begin
            pattern_thresholds[pattern_id] <= match_threshold;
        end
        current_threshold <= pattern_thresholds[pattern_id];
    end
    
    // Simple match detection (threshold >= 0.5)
    localparam signed [31:0] MATCH_THRESHOLD = 32'sh00008000;  // 0.5 in Q16.16
    assign match_detected = (current_threshold >= MATCH_THRESHOLD);
    
endmodule

// ═══════════════════════════════════════════════════════════════════════════
// BRAM Partial LUT Testbench
// ═══════════════════════════════════════════════════════════════════════════
module bram_partial_lut_tb;
    reg clk;
    reg we;
    reg [9:0] addr;
    reg [31:0] din;
    wire [31:0] dout;
    
    // Instantiate BRAM partial LUT
    bram_partial_lut dut (
        .clk(clk),
        .we(we),
        .addr(addr),
        .din(din),
        .dout(dout)
    );
    
    // Clock generation (50MHz)
    initial clk = 0;
    always #10 clk = ~clk;
    
    // Test stimulus
    initial begin
        // Initialize
        clk = 0;
        we = 0;
        addr = 10'd0;
        din = 32'd0;
        
        #20;
        
        // Write pattern matching threshold (72% = 0.72 in Q16.16)
        #20;
        we = 1;
        addr = 10'd0;
        din = 32'sh0000B851;  // 0.72 in Q16.16
        #20;
        we = 0;
        
        // Read back
        #20;
        addr = 10'd0;
        #20;
        $display("Pattern threshold: %d", dout);
        
        // Write another threshold (50% = 0.50 in Q16.16)
        #20;
        we = 1;
        addr = 10'd1;
        din = 32'sh00008000;  // 0.50 in Q16.16
        #20;
        we = 0;
        
        // Read back
        #20;
        addr = 10'd1;
        #20;
        $display("Pattern threshold: %d", dout);
        
        #100;
        $finish;
    end
endmodule

// ═══════════════════════════════════════════════════════════════════════════
// MEMS Microphone Interface (SPH0645)
// I2S/PDM digital output interface for acoustic input
// ═══════════════════════════════════════════════════════════════════════════
module mems_mic_interface (
    input  wire        clk,           // System clock (27MHz)
    input  wire        mic_clk,       // MEMS mic clock (typically 2.4MHz)
    input  wire        mic_data,      // MEMS mic data (PDM or I2S)
    input  wire        mic_lr,        // Left/Right select (I2S only)
    output reg  [31:0] audio_sample,  // Q16.16 audio sample output
    output reg         sample_valid   // Sample valid flag
    output reg  [9:0]  sample_addr    // BRAM address for pattern matching
    input  wire        pattern_we,    // Pattern match write enable
    input  wire [9:0]  pattern_addr,  // Pattern match address
    input  [31:0]      pattern_threshold  // Pattern match threshold
    output wire        pattern_match   // Pattern match detected
);
    // PDM to PCM conversion (simplified)
    reg [15:0] pdm_accumulator;
    reg [7:0]  pdm_counter;
    
    always @(posedge mic_clk) begin
        pdm_accumulator <= pdm_accumulator + {16'b0, mic_data};
        pdm_counter <= pdm_counter + 1;
        
        if (pdm_counter == 8'd255) begin
            // Convert to Q16.16 (shift by 16)
            audio_sample <= {pdm_accumulator, 16'b0};
            sample_valid <= 1'b1;
            pdm_accumulator <= 16'b0;
            pdm_counter <= 8'b0;
        end else begin
            sample_valid <= 1'b0;
        end
    end
    
    // Pattern matching address generation
    assign sample_addr = audio_sample[9:0];  // Use lower 10 bits as address
    
    // Pattern match detection
    localparam signed [31:0] MATCH_THRESHOLD = 32'sh00008000;  // 0.5 in Q16.16
    assign pattern_match = (audio_sample >= MATCH_THRESHOLD);
    
endmodule

// ═══════════════════════════════════════════════════════════════════════════
// BRAM Partial Lut with Morphic Scalar Testbench
// ═══════════════════════════════════════════════════════════════════════════
module bram_partial_lut_morphic_tb;
    reg clk;
    reg we;
    reg [9:0] addr;
    reg [31:0] din;
    wire [31:0] dout;
    reg update_enable;
    reg signed [31:0] morphic_amplitude;
    reg [9:0] pattern_addr;
    wire [31:0] pattern_match_threshold;
    
    // Instantiate BRAM partial LUT with morphic integration
    bram_partial_lut_morphic dut (
        .clk(clk),
        .we(we),
        .addr(addr),
        .din(din),
        .dout(dout),
        .update_enable(update_enable),
        .morphic_amplitude(morphic_amplitude),
        .pattern_addr(pattern_addr),
        .pattern_match_threshold(pattern_match_threshold)
    );
    
    // Clock generation (50MHz)
    initial clk = 0;
    always #10 clk = ~clk;
    
    // Test stimulus
    initial begin
        // Initialize
        clk = 0;
        we = 0;
        addr = 10'd0;
        din = 32'd0;
        update_enable = 0;
        morphic_amplitude = 32'sd0;
        pattern_addr = 10'd0;
        
        #20;
        
        // Write initial threshold (72% = 0.72 in Q16.16)
        #20;
        we = 1;
        addr = 10'd0;
        din = 32'sh0000B851;
        #20;
        we = 0;
        
        // Read back
        #20;
        addr = 10'd0;
        #20;
        $display("Initial threshold: %d", dout);
        
        // Morphic scalar update (amplitude = 10)
        #20;
        we = 1;
        addr = 10'd0;
        update_enable = 1;
        morphic_amplitude = 32'sd10;  // Amplitude = 10
        #20;
        we = 0;
        update_enable = 0;
        
        // Read back updated threshold
        #20;
        addr = 10'd0;
        #20;
        $display("Updated threshold: %d", dout);
        
        // Pattern match lookup
        #20;
        pattern_addr = 10'd0;
        #20;
        $display("Pattern match threshold: %d", pattern_match_threshold);
        
        #100;
        $finish;
    end
endmodule