Working CPP way of writing data

This commit is contained in:
2026-02-24 16:40:17 +01:00
parent 8f4e887b9d
commit 9930ce4461
10 changed files with 803 additions and 171 deletions

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rtl/core/mcu.v Normal file
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`timescale 1ns/1ps
`include "../util/clog2.vh"
module mcu #(
parameter memfile = "",
parameter memsize = 8192,
parameter sim = 1'b0
)(
input wire i_clk,
input wire i_rst,
input wire [31:0] i_GPI_A,
input wire [31:0] i_GPI_B,
input wire [31:0] i_GPI_C,
input wire [31:0] i_GPI_D,
output wire [31:0] o_GPO_A,
output wire [31:0] o_GPO_B,
output wire [31:0] o_GPO_C,
output wire [31:0] o_GPO_D
);
localparam WITH_CSR = 1;
localparam regs = 32+WITH_CSR*4;
localparam rf_width = 8;
wire rst;
wire rst_mem_reason;
wire timer_irq;
assign rst = i_rst | rst_mem_reason;
assign timer_irq = 1'b0;
// Busses
// CPU->memory
wire [31:0] wb_mem_adr;
wire [31:0] wb_mem_dat;
wire [3:0] wb_mem_sel;
wire wb_mem_we;
wire wb_mem_stb;
wire [31:0] wb_mem_rdt;
wire wb_mem_ack;
// CPU->peripherals
wire [31:0] wb_ext_adr;
wire [31:0] wb_ext_dat;
wire [3:0] wb_ext_sel;
wire wb_ext_we;
wire wb_ext_stb;
wire [31:0] wb_ext_rdt;
wire wb_ext_ack;
// CPU->RF
wire [6+WITH_CSR:0] rf_waddr;
wire [rf_width-1:0] rf_wdata;
wire rf_wen;
wire [6+WITH_CSR:0] rf_raddr;
wire [rf_width-1:0] rf_rdata;
wire rf_ren;
// combined RF and mem bus to actual RAM
wire [`CLOG2(memsize)-1:0] sram_waddr;
wire [rf_width-1:0] sram_wdata;
wire sram_wen;
wire [`CLOG2(memsize)-1:0] sram_raddr;
wire [rf_width-1:0] sram_rdata;
wire sram_ren;
// GPIO
wire [4*32-1:0] GPO;
wire [4*32-1:0] GPI;
assign o_GPO_A = GPO[32*1-1:32*0];
assign o_GPO_B = GPO[32*2-1:32*1];
assign o_GPO_C = GPO[32*3-1:32*2];
assign o_GPO_D = GPO[32*4-1:32*3];
assign GPI[32*1-1:32*0] = i_GPI_A;
assign GPI[32*2-1:32*1] = i_GPI_B;
assign GPI[32*3-1:32*2] = i_GPI_C;
assign GPI[32*4-1:32*3] = i_GPI_D;
// SERV core with mux splitting dbus into mem and ext and
// arbiter combining mem and ibus
// separate rst line to let other hardware keep core under reset
servile #(
.reset_pc(32'h0000_0000),
.reset_strategy("MINI"),
.rf_width(rf_width),
.sim(sim),
.with_csr(WITH_CSR),
.with_c(0),
.with_mdu(0)
) servile (
.i_clk(i_clk),
.i_rst(rst),
.i_timer_irq(timer_irq),
//Memory interface
.o_wb_mem_adr(wb_mem_adr),
.o_wb_mem_dat(wb_mem_dat),
.o_wb_mem_sel(wb_mem_sel),
.o_wb_mem_we(wb_mem_we),
.o_wb_mem_stb(wb_mem_stb),
.i_wb_mem_rdt(wb_mem_rdt),
.i_wb_mem_ack(wb_mem_ack),
//Extension interface
.o_wb_ext_adr(wb_ext_adr),
.o_wb_ext_dat(wb_ext_dat),
.o_wb_ext_sel(wb_ext_sel),
.o_wb_ext_we(wb_ext_we),
.o_wb_ext_stb(wb_ext_stb),
.i_wb_ext_rdt(wb_ext_rdt),
.i_wb_ext_ack(wb_ext_ack),
//RF IF
.o_rf_waddr(rf_waddr),
.o_rf_wdata(rf_wdata),
.o_rf_wen(rf_wen),
.o_rf_raddr(rf_raddr),
.o_rf_ren(rf_ren),
.i_rf_rdata(rf_rdata)
);
// WB arbiter combining RF and mem interfaces into 1
// Last 128 bytes are used for registers
servile_rf_mem_if #(
.depth(memsize),
.rf_regs(regs)
) rf_mem_if (
.i_clk (i_clk),
.i_rst (i_rst),
.i_waddr(rf_waddr),
.i_wdata(rf_wdata),
.i_wen(rf_wen),
.i_raddr(rf_raddr),
.o_rdata(rf_rdata),
.i_ren(rf_ren),
.o_sram_waddr(sram_waddr),
.o_sram_wdata(sram_wdata),
.o_sram_wen(sram_wen),
.o_sram_raddr(sram_raddr),
.i_sram_rdata(sram_rdata),
// .o_sram_ren(sram_ren),
.i_wb_adr(wb_mem_adr[`CLOG2(memsize)-1:2]),
.i_wb_stb(wb_mem_stb),
.i_wb_we(wb_mem_we) ,
.i_wb_sel(wb_mem_sel),
.i_wb_dat(wb_mem_dat),
.o_wb_rdt(wb_mem_rdt),
.o_wb_ack(wb_mem_ack)
);
memory #(
.memfile(memfile),
.depth(memsize),
.sim(sim)
) mem (
.i_clk(i_clk),
.i_waddr(sram_waddr),
.i_wdata(sram_wdata),
.i_wen(sram_wen),
.i_raddr(sram_raddr),
.o_rdata(sram_rdata),
.o_core_reset(rst_mem_reason)
);
wb_gpio_banks #(
.BASE_ADDR(32'h40000000),
.NUM_BANKS(4)
) gpio (
.i_wb_clk(i_clk),
.i_wb_rst(rst),
.i_wb_dat(wb_ext_dat),
.i_wb_adr(wb_ext_adr),
.i_wb_we(wb_ext_we),
.i_wb_stb(wb_ext_stb),
.i_wb_sel(wb_ext_sel),
.o_wb_rdt(wb_ext_rdt),
.o_wb_ack(wb_ext_ack),
.i_gpio(GPI),
.o_gpio(GPO)
);
endmodule
module jtag_mem_protocol #(
parameter aw = 8,
parameter chain = 1
)(
input wire i_clk,
input wire i_rst,
input wire [7:0] i_mem_rdata,
output reg o_mem_wen,
output reg [7:0] o_mem_wdata,
output reg [aw-1:0] o_mem_waddr,
output reg [aw-1:0] o_mem_raddr,
output reg o_core_reset
);
localparam FRAME_BITS = 42;
// Frame format (LSB-first on JTAG shift stream):
// [0] : core reset
// [1] : write (1=write, 0=read)
// [33:2] : address
// [41:34] : data
wire [31:0] cmd_addr_full;
wire cmd_reset;
wire cmd_write;
wire [7:0] cmd_data;
// JTAG interface wires
wire jtag_tck;
wire jtag_tdi;
wire jtag_drck;
wire jtag_capture;
wire jtag_shift;
wire jtag_update;
wire jtag_runtest;
wire jtag_reset;
wire jtag_sel;
// JTAG clock-domain regs
reg [FRAME_BITS-1:0] shift_q;
reg [FRAME_BITS-1:0] cmd_jtag_q;
reg update_toggle_jtag_q;
reg [FRAME_BITS-1:0] resp_meta_q;
reg [FRAME_BITS-1:0] resp_sync_q;
// Core clock-domain CDC regs
reg update_toggle_meta_q;
reg update_toggle_sync_q;
reg update_toggle_sync_d_q;
reg [FRAME_BITS-1:0] cmd_meta_q;
reg [FRAME_BITS-1:0] cmd_sync_q;
// Core clock-domain protocol state
reg [FRAME_BITS-1:0] resp_core_q;
reg read_pending_q;
reg [31:0] read_addr_full_q;
assign cmd_reset = cmd_sync_q[0];
assign cmd_write = cmd_sync_q[1];
assign cmd_addr_full = cmd_sync_q[33:2];
assign cmd_data = cmd_sync_q[41:34];
jtag_if #(
.chain(chain)
) jtag (
.i_tdo(shift_q[0]),
.o_tck(jtag_tck),
.o_tdi(jtag_tdi),
.o_drck(jtag_drck),
.o_capture(jtag_capture),
.o_shift(jtag_shift),
.o_update(jtag_update),
.o_runtest(jtag_runtest),
.o_reset(jtag_reset),
.o_sel(jtag_sel)
);
// JTAG domain: shift register and update event capture.
always @(posedge jtag_drck or posedge jtag_reset or posedge i_rst) begin
if (jtag_reset || i_rst) begin
shift_q <= {FRAME_BITS{1'b0}};
resp_meta_q <= {FRAME_BITS{1'b0}};
resp_sync_q <= {FRAME_BITS{1'b0}};
end else begin
resp_meta_q <= resp_core_q;
resp_sync_q <= resp_meta_q;
if (jtag_sel && jtag_capture) begin
shift_q <= resp_sync_q;
end else if (jtag_sel && jtag_shift) begin
shift_q <= {jtag_tdi, shift_q[FRAME_BITS-1:1]};
end
end
end
always @(posedge jtag_update or posedge jtag_reset or posedge i_rst) begin
if (jtag_reset || i_rst) begin
cmd_jtag_q <= {FRAME_BITS{1'b0}};
update_toggle_jtag_q <= 1'b0;
end else if (jtag_sel) begin
cmd_jtag_q <= shift_q;
update_toggle_jtag_q <= ~update_toggle_jtag_q;
end
end
// Core domain: receive command and execute against RAM port-B.
always @(posedge i_clk or posedge i_rst) begin
if (i_rst) begin
update_toggle_meta_q <= 1'b0;
update_toggle_sync_q <= 1'b0;
update_toggle_sync_d_q <= 1'b0;
cmd_meta_q <= {FRAME_BITS{1'b0}};
cmd_sync_q <= {FRAME_BITS{1'b0}};
o_mem_wen <= 1'b0;
o_mem_wdata <= 8'h00;
o_mem_waddr <= {aw{1'b0}};
o_mem_raddr <= {aw{1'b0}};
o_core_reset <= 1'b0;
resp_core_q <= {FRAME_BITS{1'b0}};
read_pending_q <= 1'b0;
read_addr_full_q <= 32'h0000_0000;
end else begin
// Defaults are one-cycle strobes for write/reset.
o_mem_wen <= 1'b0;
o_core_reset <= 1'b0;
update_toggle_meta_q <= update_toggle_jtag_q;
update_toggle_sync_q <= update_toggle_meta_q;
update_toggle_sync_d_q <= update_toggle_sync_q;
cmd_meta_q <= cmd_jtag_q;
cmd_sync_q <= cmd_meta_q;
// Complete pending read (port-B read is synchronous).
if (read_pending_q) begin
read_pending_q <= 1'b0;
resp_core_q[0] <= 1'b0;
resp_core_q[1] <= 1'b0;
resp_core_q[33:2] <= read_addr_full_q;
resp_core_q[41:34] <= i_mem_rdata;
end
// New JTAG command arrived.
if (update_toggle_sync_q ^ update_toggle_sync_d_q) begin
if (cmd_reset) begin
o_core_reset <= 1'b1;
end
if (cmd_write) begin
o_mem_waddr <= cmd_addr_full[aw-1:0];
o_mem_wdata <= cmd_data;
o_mem_wen <= 1'b1;
resp_core_q[0] <= cmd_reset;
resp_core_q[1] <= 1'b1;
resp_core_q[33:2] <= cmd_addr_full;
resp_core_q[41:34] <= cmd_data;
end else begin
o_mem_raddr <= cmd_addr_full[aw-1:0];
read_pending_q <= 1'b1;
read_addr_full_q <= cmd_addr_full;
end
end
end
end
// Keep lint quiet for currently-unused JTAG outputs.
wire _unused_tck;
wire _unused_runtest;
assign _unused_tck = jtag_tck;
assign _unused_runtest = jtag_runtest;
endmodule
module memory #(
parameter memfile = "",
parameter depth = 256,
parameter sim = 1'b0,
localparam aw = `CLOG2(depth)
)(
input wire i_clk,
input wire [aw-1:0] i_waddr,
input wire [7:0] i_wdata,
input wire i_wen,
input wire [aw-1:0] i_raddr,
output reg [7:0] o_rdata,
output wire o_core_reset
);
// The actual memory
reg [7:0]mem [0:depth-1];
// Second interface
wire wen_b;
wire [7:0] wdata_b;
wire [aw-1:0] waddr_b;
reg [7:0] rdata_b;
wire [aw-1:0] raddr_b;
jtag_mem_protocol #(
.aw(aw),
.chain(1)
) jtag_mem (
.i_clk(i_clk),
.i_rst(1'b0),
.i_mem_rdata(rdata_b),
.o_mem_wen(wen_b),
.o_mem_wdata(wdata_b),
.o_mem_waddr(waddr_b),
.o_mem_raddr(raddr_b),
.o_core_reset(o_core_reset)
);
// Read/Write
always @(posedge i_clk) begin
// main interface
if (i_wen)
mem[i_waddr] <= i_wdata;
o_rdata <= mem[i_raddr];
// second interface
if (wen_b)
mem[waddr_b] <= wdata_b;
rdata_b <= mem[raddr_b];
end
// Preload memory
integer i;
initial begin
if(sim==1'b1) begin
for (i = 0; i < depth; i = i + 1)
mem[i] = 8'h00;
end
if(|memfile) begin
$display("Preloading %m from %s", memfile);
$readmemh(memfile, mem);
end
end
endmodule