180 lines
3.8 KiB
Verilog

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer:
//
// Create Date: 21:57:50 08/25/2009
// Design Name:
// Module Name: mcu_cmd
// Project Name:
// Target Devices:
// Tool versions:
// Description:
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
//
//////////////////////////////////////////////////////////////////////////////////
module mcu_cmd(
input clk,
input cmd_ready,
input param_ready,
input [7:0] cmd_data,
input [7:0] param_data,
output mcu_rrq,
output mcu_wrq,
input mcu_rq_rdy,
output [7:0] mcu_data_out,
input [7:0] mcu_data_in,
output [7:0] spi_data_out,
input [31:0] spi_byte_cnt,
input [2:0] spi_bit_cnt,
output [23:0] addr_out,
output [23:0] saveram_mask_out,
output [23:0] rom_mask_out
);
reg [7:0] MCU_DATA_OUT_BUF;
reg [7:0] MCU_DATA_IN_BUF;
reg [2:0] mcu_nextaddr_buf;
wire mcu_nextaddr;
reg [23:0] SAVERAM_MASK;
reg [23:0] ROM_MASK;
reg [23:0] ADDR_OUT_BUF;
assign spi_data_out = MCU_DATA_IN_BUF;
initial begin
ADDR_OUT_BUF = 0;
end
// command interpretation
always @(posedge clk) begin
if (param_ready) begin
casex (cmd_data[7:0])
8'h1x:
case (spi_byte_cnt)
32'h2:
ROM_MASK[23:16] <= param_data;
32'h3:
ROM_MASK[15:8] <= param_data;
32'h4:
ROM_MASK[7:0] <= param_data;
endcase
8'h2x:
case (spi_byte_cnt)
32'h2:
SAVERAM_MASK[23:16] <= param_data;
32'h3:
SAVERAM_MASK[15:8] <= param_data;
32'h4:
SAVERAM_MASK[7:0] <= param_data;
endcase
8'h9x:
MCU_DATA_OUT_BUF <= param_data;
endcase
end
end
always @(posedge clk) begin
if(param_ready && cmd_data[7:4] == 4'h0) begin
case (spi_byte_cnt)
32'h2: begin
ADDR_OUT_BUF[23:16] <= param_data;
ADDR_OUT_BUF[15:0] <= 16'b0;
end
32'h3:
ADDR_OUT_BUF[15:8] <= param_data;
32'h4:
ADDR_OUT_BUF[7:0] <= param_data;
endcase
end else if ((mcu_nextaddr & (cmd_data[7:5] == 3'h4)
&& (cmd_data[3])
&& (spi_byte_cnt >= (32'h1+cmd_data[4])))
)
begin
ADDR_OUT_BUF <= ADDR_OUT_BUF + 1;
end
end
// value fetch during last SPI bit
always @(posedge clk) begin
if (cmd_data[7:4] == 4'h8 && mcu_nextaddr)
MCU_DATA_IN_BUF <= mcu_data_in;
else if (cmd_ready | param_ready /* bit_cnt == 7 */) begin
if (cmd_data[7:0] == 8'hF0)
MCU_DATA_IN_BUF <= 8'hA5;
else if (cmd_data[7:0] == 8'hFF)
MCU_DATA_IN_BUF <= param_data;
end
end
// nextaddr pulse generation
always @(posedge clk) begin
mcu_nextaddr_buf <= {mcu_nextaddr_buf[1:0], mcu_rq_rdy};
end
parameter ST_RQ = 2'b01;
parameter ST_IDLE = 2'b10;
reg [1:0] rrq_state;
initial rrq_state = ST_IDLE;
reg mcu_rrq_r;
reg [1:0] wrq_state;
initial wrq_state = ST_IDLE;
reg mcu_wrq_r;
always @(posedge clk) begin
case(rrq_state)
ST_IDLE: begin
if((param_ready | cmd_ready) && cmd_data[7:4] == 4'h8) begin
mcu_rrq_r <= 1'b1;
rrq_state <= ST_RQ;
end else
rrq_state <= ST_IDLE;
end
ST_RQ: begin
mcu_rrq_r <= 1'b0;
rrq_state <= ST_IDLE;
end
endcase
end
always @(posedge clk) begin
case(wrq_state)
ST_IDLE: begin
if(param_ready && cmd_data[7:4] == 4'h9) begin
mcu_wrq_r <= 1'b1;
wrq_state <= ST_RQ;
end else
wrq_state <= ST_IDLE;
end
ST_RQ: begin
mcu_wrq_r <= 1'b0;
wrq_state <= ST_IDLE;
end
endcase
end
// trigger for nextaddr
assign mcu_nextaddr = mcu_nextaddr_buf == 2'b01;
assign mcu_rrq = mcu_rrq_r;
assign mcu_wrq = mcu_wrq_r;
assign addr_out = ADDR_OUT_BUF;
assign mcu_data_out = MCU_DATA_OUT_BUF;
assign rom_mask_out = ROM_MASK;
assign saveram_mask_out = SAVERAM_MASK;
assign DBG_mcu_nextaddr = mcu_nextaddr;
endmodule