// retroDE_ps2 — tb_gs_textured_sprite (Brick 1) // // FIRST textured-sprite test: drives a PSMCT32 DECAL textured SPRITE // through gs_stub's raster pipeline and verifies the framebuffer // pixels equal the preloaded texture texels. // // Datapath under test (Brick 1): // PRIM.TME=1 + TEX0_1(texture-side) + UV per-vertex + SPRITE // -> per-pixel linear (u,v) interpolation // -> gs_texture_unit (gs_texel_addr + PSMCT32 DECAL sample) // -> texel REPLACES the flat sprite color at emit. // // To isolate the sampling datapath from the texture-UPLOAD path, the // texture is PRELOADED DIRECTLY into vram_stub at the TBP0-derived // base (TBP0*256, the convention gs_stub documents + the upload path // uses). A follow-on chapter reconciles the BITBLT/TRX upload path. // // Geometry / mapping (chosen so the mapping is the identity texel(x,y)): // SPRITE endpoints (0,0)->(3,3) => 4x4 fill. // UV endpoints (0,0)->(3,3) => u=x, v=y across the sprite. // Framebuffer: FBP=0, FBW=1, PSM=PSMCT32. Stride = 64*4 = 256 B/row. // Texture: TBP0=8 (base 2048 B), TBW=1 (64 texels/row), PSM=PSMCT32. // // PASS criteria: // - 16 raster_pixel_emit pulses. // - Each framebuffer pixel (x,y) == preloaded texel(x,y). // - A NON-textured control SPRITE (TME=0) at a different FB region // still emits the FLAT color (proves the TME=0 path is unchanged). `timescale 1ns/1ps module tb_gs_textured_sprite; logic clk; logic rst_n; initial clk = 1'b0; always #5 clk = ~clk; // gs_stub IO logic gif_reg_wr_en; logic [7:0] gif_reg_num; logic [63:0] gif_reg_data; logic [7:0] bg_r, bg_g, bg_b; logic [63:0] pmode_q, dispfb1_q, display1_q; logic [63:0] prim_q, rgbaq_q, xyz2_q, xyzf2_q, frame_1_q, zbuf_1_q; logic [63:0] tex0_1_q; logic [13:0] tex0_1_cbp_q; logic [3:0] tex0_1_cpsm_q; logic tex0_1_csm_q; logic [4:0] tex0_1_csa_q; logic [2:0] tex0_1_cld_q; logic tex0_1_wr_q; logic [63:0] bitbltbuf_q, trxpos_q, trxreg_q, trxdir_q; logic trxdir_wr_q; logic prim_complete; logic [31:0] prim_complete_count; logic [63:0] prim_v0_q, prim_v1_q, prim_v2_q; logic [63:0] prim_color_q; logic [63:0] prim_color_v0_q, prim_color_v1_q, prim_color_v2_q; trace_pkg::vertex_t prim_v0_decoded_q, prim_v1_decoded_q, prim_v2_decoded_q; trace_pkg::color_t prim_v0_color_decoded_q, prim_v1_color_decoded_q, prim_v2_color_decoded_q; logic pixel_emit; logic [31:0] pixel_emit_count; logic [11:0] pixel_x_q, pixel_y_q; logic [63:0] pixel_color_q; logic [8:0] pixel_fbp_q; logic [5:0] pixel_fbw_q, pixel_psm_q; logic [31:0] pixel_fb_addr_q; logic raster_pixel_emit; logic [31:0] raster_pixel_emit_count; logic [11:0] raster_pixel_x_q, raster_pixel_y_q; logic [63:0] raster_pixel_color_q; logic [31:0] raster_pixel_fb_addr_q; logic [3:0] raster_pixel_be_q; logic [31:0] raster_pixel_mask_q; logic [5:0] raster_pixel_psm_q; logic raster_active; logic raster_overflow; logic raster_fifo_full; logic raster_degenerate; logic tex_rd_en; logic [31:0] tex_rd_addr; logic [31:0] tex_rd_data; logic gs_ev_valid; trace_pkg::subsys_e gs_ev_subsys; trace_pkg::event_e gs_ev_event; logic [63:0] gs_ev_arg0, gs_ev_arg1, gs_ev_arg2, gs_ev_arg3; logic [31:0] gs_ev_flags; gs_stub u_gs ( .clk(clk), .rst_n(rst_n), .reg_wr_en(1'b0), .reg_wr_addr(16'd0), .reg_wr_data(64'd0), .gif_reg_wr_en(gif_reg_wr_en), .gif_reg_num(gif_reg_num), .gif_reg_data(gif_reg_data), .bg_r(bg_r), .bg_g(bg_g), .bg_b(bg_b), .pmode_q(pmode_q), .dispfb1_q(dispfb1_q), .display1_q(display1_q), .prim_q(prim_q), .rgbaq_q(rgbaq_q), .xyz2_q(xyz2_q), .xyzf2_q(xyzf2_q), .frame_1_q(frame_1_q), .zbuf_1_q(zbuf_1_q), .tex0_1_q(tex0_1_q), .tex0_1_cbp_q(tex0_1_cbp_q), .tex0_1_cpsm_q(tex0_1_cpsm_q), .tex0_1_csm_q(tex0_1_csm_q), .tex0_1_csa_q(tex0_1_csa_q), .tex0_1_cld_q(tex0_1_cld_q), .tex0_1_wr_q(tex0_1_wr_q), .bitbltbuf_q(bitbltbuf_q), .trxpos_q(trxpos_q), .trxreg_q(trxreg_q), .trxdir_q(trxdir_q), .trxdir_wr_q(trxdir_wr_q), .prim_complete(prim_complete), .prim_complete_count(prim_complete_count), .prim_v0_q(prim_v0_q), .prim_v1_q(prim_v1_q), .prim_v2_q(prim_v2_q), .prim_color_q(prim_color_q), .prim_color_v0_q(prim_color_v0_q), .prim_color_v1_q(prim_color_v1_q), .prim_color_v2_q(prim_color_v2_q), .prim_v0_decoded_q(prim_v0_decoded_q), .prim_v1_decoded_q(prim_v1_decoded_q), .prim_v2_decoded_q(prim_v2_decoded_q), .prim_v0_color_decoded_q(prim_v0_color_decoded_q), .prim_v1_color_decoded_q(prim_v1_color_decoded_q), .prim_v2_color_decoded_q(prim_v2_color_decoded_q), .pixel_emit(pixel_emit), .pixel_emit_count(pixel_emit_count), .pixel_x_q(pixel_x_q), .pixel_y_q(pixel_y_q), .pixel_color_q(pixel_color_q), .pixel_fbp_q(pixel_fbp_q), .pixel_fbw_q(pixel_fbw_q), .pixel_psm_q(pixel_psm_q), .pixel_fb_addr_q(pixel_fb_addr_q), .raster_pixel_emit(raster_pixel_emit), .raster_pixel_emit_count(raster_pixel_emit_count), .raster_pixel_x_q(raster_pixel_x_q), .raster_pixel_y_q(raster_pixel_y_q), .raster_pixel_color_q(raster_pixel_color_q), .raster_pixel_fb_addr_q(raster_pixel_fb_addr_q), .raster_pixel_be_q(raster_pixel_be_q), .raster_pixel_mask_q(raster_pixel_mask_q), .raster_pixel_psm_q(raster_pixel_psm_q), .raster_active(raster_active), .raster_overflow(raster_overflow), .raster_fifo_full(raster_fifo_full), .raster_degenerate(raster_degenerate), .tex_rd_en(tex_rd_en), .tex_rd_addr(tex_rd_addr), .tex_rd_data(tex_rd_data), .ev_valid(gs_ev_valid), .ev_subsys(gs_ev_subsys), .ev_event(gs_ev_event), .ev_arg0(gs_ev_arg0), .ev_arg1(gs_ev_arg1), .ev_arg2(gs_ev_arg2), .ev_arg3(gs_ev_arg3), .ev_flags(gs_ev_flags) ); // VRAM. Port 0 = raster write + TB readback. Port 1 (read2) = // texel fetch. In a full integration read2 is muxed between // clut_loader_stub (CLUT load at TEX0 commit) and gs_stub's texel // fetch (during the scan); clut_loader is not instantiated here, // so read2 is dedicated to the texel port. The mux is documented // in gs_stub's tex_rd_* port comment. logic [31:0] vram_read_addr; logic [31:0] vram_read_data; localparam int VRAM_BYTES = 8192; vram_stub #(.BYTES(VRAM_BYTES)) u_vram ( .clk(clk), .rst_n(rst_n), .write_en (raster_pixel_emit), .write_addr(raster_pixel_fb_addr_q), .write_data(raster_pixel_color_q[31:0]), .write_be (raster_pixel_be_q), .write_mask(raster_pixel_mask_q), .read_addr (vram_read_addr), .read_data (vram_read_data), .read2_addr(tex_rd_addr), .read2_data(tex_rd_data) ); int errors; int textured_emit_seen; initial begin errors = 0; textured_emit_seen = 0; end // ----- GIF register numbers ----- localparam logic [7:0] R_PRIM = 8'h00; localparam logic [7:0] R_RGBAQ = 8'h01; localparam logic [7:0] R_UV = 8'h03; localparam logic [7:0] R_XYZ2 = 8'h05; localparam logic [7:0] R_TEX0_1 = 8'h06; localparam logic [7:0] R_FRAME_1 = 8'h4C; // PRIM: type=6 (SPRITE) at [2:0]; TME at bit 4. localparam logic [63:0] PRIM_SPRITE_TEX = 64'd6 | (64'd1 << 4); // SPRITE + TME localparam logic [63:0] PRIM_SPRITE_FLAT = 64'd6; // SPRITE, no TME // FRAME_1: FBP[8:0]=0, FBW[21:16]=1, PSM[29:24]=PSMCT32(0x00). localparam logic [63:0] FRAME_1_FB0 = 64'h0000_0000_0001_0000; // A second FB region for the flat control sprite: FBP=1 (2048 B). localparam logic [63:0] FRAME_1_FB1 = 64'h0000_0000_0001_0001; // TEX0_1 texture-side: TBP0[13:0]=8, TBW[19:14]=1, PSM[25:20]=0. // TBP0=8 -> base bytes = 8*256 = 2048. localparam logic [13:0] TEX_TBP0 = 14'd8; localparam logic [5:0] TEX_TBW = 6'd1; localparam logic [63:0] TEX0_VAL = {30'd0, 6'd0 /*TH*/, 4'd0 /*TW*/, 6'd0 /*PSM*/, TEX_TBW, TEX_TBP0}; localparam logic [31:0] TEX_BASE_BYTES = 32'd8 * 32'd256; // 2048 localparam int TEX_ROW_TEXELS = 64; // TBW*64 // Flat control color. localparam logic [63:0] FLAT_RGBAQ = 64'h0000_0000_8011_2233; // ABGR=0x80112233 localparam int SPRITE_W = 4; localparam int SPRITE_H = 4; localparam int FB0_STRIDE = 64 * 4; // FBW=1 -> 64 px/row * 4 B localparam int FB1_BASE = 2048; // FBP=1 -> 1*2048 // Expected texel for (x,y): a recognizable pattern. function automatic logic [31:0] texel(input int x, input int y); return 32'hFF000000 | (x << 8) | (y << 16) | 32'h00000040; endfunction // ----- drive helpers ----- task automatic step_drive(input logic wr_en, input logic [7:0] num, input logic [63:0] data); @(negedge clk); gif_reg_wr_en = wr_en; gif_reg_num = num; gif_reg_data = data; @(posedge clk); endtask task automatic drive_reg(input logic [7:0] num, input logic [63:0] data); step_drive(1'b1, num, data); endtask task automatic drive_idle(); step_drive(1'b0, 8'd0, 64'd0); endtask function automatic logic [63:0] xyz2_data(input logic [11:0] x_int, input logic [11:0] y_int); return {32'd0, y_int, 4'd0, x_int, 4'd0}; endfunction // UV reg: U=[13:0], V=[27:14], 10.4 fixed-point. Integer u,v. function automatic logic [63:0] uv_data(input int ui, input int vi); logic [13:0] u_fp, v_fp; u_fp = 14'(ui) << 4; v_fp = 14'(vi) << 4; return {36'd0, v_fp, u_fp}; endfunction // Read a 32-bit word from VRAM port 0 (combinational read). The // settle delay lives in the caller (a task), not in a function. task automatic vram_word(input logic [31:0] byte_addr, output logic [31:0] word); vram_read_addr = byte_addr; #1; word = vram_read_data; endtask // Preload a 32-bit little-endian word directly into the VRAM // backing store (raster is idle during preload, so a direct mem // poke is the simplest texture-upload bypass). Static task: a // hierarchical force/poke on automatic-task locals is illegal in // iverilog 12, and a direct mem write needs no force at all. task automatic force_word(input logic [31:0] addr, input logic [31:0] data); u_vram.mem[addr + 0] = data[7:0]; u_vram.mem[addr + 1] = data[15:8]; u_vram.mem[addr + 2] = data[23:16]; u_vram.mem[addr + 3] = data[31:24]; endtask // ----- observer: count textured emits ----- always_ff @(posedge clk) begin if (rst_n && raster_pixel_emit && (raster_pixel_psm_q == 6'h00) && (raster_pixel_fb_addr_q < FB1_BASE)) begin textured_emit_seen <= textured_emit_seen + 1; end end integer x, y; logic [31:0] got, exp; initial begin rst_n = 1'b0; gif_reg_wr_en = 1'b0; gif_reg_num = 8'd0; gif_reg_data = 64'd0; vram_read_addr = 32'd0; repeat (4) @(posedge clk); rst_n = 1'b1; repeat (2) @(posedge clk); // --- Preload the texture DIRECTLY into VRAM at TBP0*256. --- // (Bypasses BITBLT/TRX upload — see header + gs_stub TODO.) for (y = 0; y < SPRITE_H; y++) begin for (x = 0; x < SPRITE_W; x++) begin logic [31:0] addr; addr = TEX_BASE_BYTES + ((y * TEX_ROW_TEXELS + x) * 4); // poke 4 bytes little-endian via the write port force_word(addr, texel(x, y)); end end // =========================================================== // 1) TEXTURED SPRITE // =========================================================== drive_reg(R_PRIM, PRIM_SPRITE_TEX); drive_reg(R_FRAME_1, FRAME_1_FB0); drive_reg(R_TEX0_1, TEX0_VAL); drive_reg(R_RGBAQ, FLAT_RGBAQ); // would-be flat color (must be overridden) // vertex 0: UV(0,0) at screen (0,0) drive_reg(R_UV, uv_data(0, 0)); drive_reg(R_XYZ2, xyz2_data(12'd0, 12'd0)); // vertex 1 (closing): UV(3,3) at screen (3,3) drive_reg(R_UV, uv_data(SPRITE_W - 1, SPRITE_H - 1)); drive_reg(R_XYZ2, xyz2_data(12'(SPRITE_W - 1), 12'(SPRITE_H - 1))); drive_idle(); wait (raster_active == 1'b1); wait (raster_active == 1'b0); repeat (10) @(posedge clk); if (raster_pixel_emit_count != 32'(SPRITE_W * SPRITE_H)) begin $error("textured sprite: expected %0d emits, got %0d", SPRITE_W * SPRITE_H, raster_pixel_emit_count); errors = errors + 1; end if (textured_emit_seen != SPRITE_W * SPRITE_H) begin $error("textured emit observer count=%0d (expected %0d)", textured_emit_seen, SPRITE_W * SPRITE_H); errors = errors + 1; end // Verify each FB pixel == preloaded texel(x,y). for (y = 0; y < SPRITE_H; y++) begin for (x = 0; x < SPRITE_W; x++) begin logic [31:0] addr; addr = (y * FB0_STRIDE) + (x * 4); vram_word(addr, got); exp = texel(x, y); if (got !== exp) begin $error("textured FB(%0d,%0d)@0x%08x got 0x%08x expected 0x%08x", x, y, addr, got, exp); errors = errors + 1; end end end // =========================================================== // 2) FLAT CONTROL SPRITE (TME=0) — proves unchanged path. // =========================================================== drive_reg(R_PRIM, PRIM_SPRITE_FLAT); drive_reg(R_FRAME_1, FRAME_1_FB1); drive_reg(R_RGBAQ, FLAT_RGBAQ); drive_reg(R_XYZ2, xyz2_data(12'd0, 12'd0)); drive_reg(R_XYZ2, xyz2_data(12'(SPRITE_W - 1), 12'(SPRITE_H - 1))); drive_idle(); wait (raster_active == 1'b1); wait (raster_active == 1'b0); repeat (10) @(posedge clk); // Flat sprite landed in FB1 — every pixel == FLAT color low32. for (y = 0; y < SPRITE_H; y++) begin for (x = 0; x < SPRITE_W; x++) begin logic [31:0] addr; addr = FB1_BASE + (y * FB0_STRIDE) + (x * 4); vram_word(addr, got); exp = FLAT_RGBAQ[31:0]; if (got !== exp) begin $error("flat FB(%0d,%0d)@0x%08x got 0x%08x expected 0x%08x", x, y, addr, got, exp); errors = errors + 1; end end end $display("[tb_gs_textured_sprite] sprite=%0dx%0d tex_base=0x%08x emits=%0d textured=%0d", SPRITE_W, SPRITE_H, TEX_BASE_BYTES, raster_pixel_emit_count, textured_emit_seen); if (errors == 0) $display("[tb_gs_textured_sprite] PASS"); else $display("[tb_gs_textured_sprite] FAIL"); $finish; end initial begin #5000000; $error("[tb_gs_textured_sprite] timeout"); $finish; end endmodule : tb_gs_textured_sprite