This commit is contained in:
Bee 2023-11-18 03:03:52 -05:00
parent 0794824fcd
commit 51ecf47862
6 changed files with 187 additions and 49 deletions

View file

@ -14,6 +14,7 @@ module Beepo #(
localparam FETCHI = 1; // Instruction is fetched, start fetching first argument
localparam FETCHA = 2; // Argument byte is fetched
localparam EXEC = 3; // Start running
localparam MEMR = 4; // Transferring bytes between memory and registers
localparam DONE = 7; // Done executing
// Argument types
@ -33,13 +34,12 @@ module Beepo #(
localparam NUM_REGS = 4;
reg [2:0] r_state = IDLE;
reg r_fetching = 0; // counter for waiting before reading from memory
reg [63:0] r_tick = 0;
// Registers
reg [63:0] r_pc = PC_START; // program counter
reg [63:0] r_pc_latch = PC_START; // address input to ROM
reg [63:0] r_registers [0:NUM_REGS]; // up to 255 modifiable registers
reg [63:0] r_registers [1:NUM_REGS]; // up to 255 modifiable registers
reg [7:0] r_instr; // the current instruction
reg [7:0] r_arg_regs [0:3]; // register arguments
reg [63:0] r_arg_imm = 0; // immediate argument
@ -52,7 +52,16 @@ module Beepo #(
reg [3:0] r_arg_current_type = 8; // the type of the current argument
reg [5:0] r_arg_bit = 0; // the current lower bit index being fetched for the current argument
wire [7:0] w_mem_fetch;
reg r_bus_wre = 0;
reg [7:0] r_bus_in = 0;
reg [4:0] r_bus_bytes = 1; // the number of bytes to transfer on the bus
reg [7:0] r_bus_index = 0; // the index of the byte in transfer
reg [7:0] r_bus_reg = 0; // the register currently used in transfer
reg r_bus_start = 0; // pulsed high when the bus should start a transfer
reg r_bus_trans = 0; // trans rights (the bus is executing a transfer instruction)
wire [63:0] w_bus_addr = r_bus_trans ? r_arg_addr : r_pc_latch;
wire [4:0] w_bus_bytes = r_bus_trans ? r_bus_bytes : 1;
wire [7:0] w_bus_fetch;
genvar i;
@ -65,20 +74,23 @@ module Beepo #(
always @(posedge i_clk) r_tick <= r_tick + 1;
always @(posedge i_clk) begin
if (r_fetching) r_fetching <= r_fetching + 1;
else case (r_state)
if (w_bus_ready == 0) begin
r_bus_start <= 0;
r_bus_trans <= r_bus_trans & ~w_bus_ready;
end else case (r_state)
IDLE: begin
r_pc_latch <= r_pc;
r_pc <= r_pc + 1;
r_fetching <= 1;
r_bus_start <= 1;
r_state <= FETCHI;
r_bus_wre <= 0;
end
FETCHI: begin
r_instr <= w_mem_fetch;
r_instr <= w_bus_fetch;
r_arg_index <= 0;
r_arg_bit <= 0;
case (w_mem_fetch)
case (w_bus_fetch)
`TX: r_arg_types_packed = `TX_ARGS;
`NOP: r_arg_types_packed = `NOP_ARGS;
`ADD8: r_arg_types_packed = `ADD8_ARGS;
@ -93,6 +105,8 @@ module Beepo #(
`LI16: r_arg_types_packed = `LI16_ARGS;
`LI32: r_arg_types_packed = `LI32_ARGS;
`LI64: r_arg_types_packed = `LI64_ARGS;
`LD: r_arg_types_packed = `LD_ARGS;
`ST: r_arg_types_packed = `ST_ARGS;
default: r_arg_types_packed = {ARG_N, ARG_N, ARG_N, ARG_N};
endcase
@ -100,7 +114,7 @@ module Beepo #(
r_state <= FETCHA;
r_pc_latch <= r_pc;
r_pc <= r_pc + 1;
r_fetching <= 1;
r_bus_start <= 1;
r_arg_bytes <= ARG_SIZES[r_arg_types_packed[15:12]*4+:4];
r_arg_current_type <= r_arg_types_packed[15:12];
@ -122,19 +136,19 @@ module Beepo #(
if (r_arg_current_type == ARG_N) r_state <= IDLE;
else begin
case (r_arg_current_type)
ARG_R: r_arg_regs[r_arg_index] <= w_mem_fetch;
ARG_O: r_arg_addr[r_arg_bit+:8] <= w_mem_fetch;
ARG_P: r_arg_addr[r_arg_bit+:8] <= w_mem_fetch;
ARG_B: r_arg_imm[r_arg_bit+:8] <= w_mem_fetch;
ARG_H: r_arg_imm[r_arg_bit+:8] <= w_mem_fetch;
ARG_W: r_arg_imm[r_arg_bit+:8] <= w_mem_fetch;
ARG_D: r_arg_imm[r_arg_bit+:8] <= w_mem_fetch;
ARG_A: r_arg_addr[r_arg_bit+:8] <= w_mem_fetch;
ARG_R: r_arg_regs[r_arg_index] <= w_bus_fetch;
ARG_O: r_arg_addr[r_arg_bit+:8] <= w_bus_fetch;
ARG_P: r_arg_addr[r_arg_bit+:8] <= w_bus_fetch;
ARG_B: r_arg_imm[r_arg_bit+:8] <= w_bus_fetch;
ARG_H: r_arg_imm[r_arg_bit+:8] <= w_bus_fetch;
ARG_W: r_arg_imm[r_arg_bit+:8] <= w_bus_fetch;
ARG_D: r_arg_imm[r_arg_bit+:8] <= w_bus_fetch;
ARG_A: r_arg_addr[r_arg_bit+:8] <= w_bus_fetch;
endcase
r_pc_latch <= r_pc;
r_pc <= r_pc + 1;
r_fetching <= 1;
r_bus_start <= 1;
r_arg_bytes = r_arg_bytes - 1;
r_arg_bit <= r_arg_bit + 8;
@ -143,21 +157,11 @@ module Beepo #(
r_arg_index = r_arg_index + 1;
r_arg_current_type = r_arg_types[r_arg_index];
if (r_arg_current_type == ARG_N) r_state <= EXEC;
// Execute when there is no next argument or r_arg_index has overflowed
if (r_arg_current_type == ARG_N || r_arg_index == 0) r_state <= EXEC;
else begin
r_arg_bit <= 0;
r_arg_bit <= 0;
r_arg_bytes <= ARG_SIZES[r_arg_current_type*4+:4];
case (r_arg_current_type)
ARG_R: r_arg_regs[r_arg_index] <= 0;
ARG_O: r_arg_addr[r_arg_bit-1] <= 0;
ARG_P: r_arg_addr[r_arg_bit-1] <= 0;
ARG_B: r_arg_imm[r_arg_bit-1] <= 0;
ARG_H: r_arg_imm[r_arg_bit-1] <= 0;
ARG_W: r_arg_imm[r_arg_bit-1] <= 0;
ARG_D: r_arg_imm[r_arg_bit-1] <= 0;
ARG_A: r_arg_addr[r_arg_bit-1] <= 0;
endcase
end
end
end
@ -180,13 +184,57 @@ module Beepo #(
`LI16: set_register(r_arg_regs[0], r_arg_imm);
`LI32: set_register(r_arg_regs[0], r_arg_imm);
`LI64: set_register(r_arg_regs[0], r_arg_imm);
`LD: begin
if (r_arg_imm > 0) begin
r_arg_addr <= r_arg_addr + r_registers[r_arg_regs[1]];
r_bus_index <= 0;
r_bus_reg <= r_arg_regs[0];
r_state <= MEMR;
r_bus_start <= 1;
r_bus_trans <= 1;
r_bus_bytes <= 1;
end
end
`ST: begin
if (r_arg_imm > 0) begin
r_arg_addr <= r_arg_addr + r_registers[r_arg_regs[1]];
r_bus_index <= 0;
r_bus_reg <= r_arg_regs[0];
r_bus_wre <= 1;
r_bus_in <= r_registers[r_arg_regs[0]][0+:8];
r_state <= MEMR;
r_bus_start <= 1;
r_bus_trans <= 1;
r_bus_bytes <= 1;
end
end
endcase
end
MEMR: begin
case (r_instr)
`LD: set_register(r_arg_regs[0], w_bus_fetch);
`ST: r_bus_in <= r_registers[r_arg_regs[0]][r_bus_index];
endcase
if (r_arg_imm == 1) begin
// reached the end of the transfer
r_bus_wre <= 0;
r_state <= FETCHI;
end else begin
if (r_bus_index == 6) begin
// reached the end of this register
r_bus_reg <= r_bus_reg + 1;
end
r_arg_addr <= r_arg_addr + 1;
r_arg_imm <= r_arg_imm - 1;
r_bus_start <= 1;
r_bus_trans <= 1;
end
end
endcase
end
task automatic set_register(
input [7:0] being_set,
input [63:0] setting_to
@ -194,23 +242,29 @@ module Beepo #(
if (being_set != 0) r_registers[being_set] = setting_to;
endtask
task automatic set_reg_byte(
input [7:0] being_set,
input [2:0] byte_idx,
input [7:0] setting_to
);
if (being_set != 0) r_registers[being_set][byte_idx*8+:8] = setting_to;
endtask
Multi7 display (
.i_clk(i_clk),
.i_hex({r_registers[1][15:0]}),
.o_segments_drive(o_segments_drive),
.o_displays_neg(o_displays_neg)
);
// TODO: Bus
// For now this is just ROM
spMem memory (
.dout(w_mem_fetch), //output [7:0] dout
.clk(i_clk), //input clk
.oce(1'b0), //input oce (unused)
.ce(1'b1), //input ce
.reset(1'b0), //input reset
.wre(1'b0), //input wre (write enable)
.ad(r_pc_latch[0+:32]), //input [15:0] ad
.din(1'b0) //input [7:0] din
Bus bus (
.i_clk(i_clk),
.i_addr(w_bus_addr),
.i_in(r_bus_in),
.i_flags(r_bus_wre),
.i_size(r_bus_bytes),
.i_start(r_bus_start),
.o_ready(w_bus_ready),
.o_out(w_bus_fetch)
);
endmodule

71
src/bus.v Normal file
View file

@ -0,0 +1,71 @@
// To read:
// 1. Set i_addr to start address
// 2. Set i_flags.0 to 0
// 3. Set i_size to number of bytes to read
// 4. Pulse i_start high
// 5. When o_ready goes high, the read data will be in o_out
// To write:
// 1. Set i_addr to start address
// 2. Set i_in to the data to write
// 3. Set i_flags.0 to 1
// 4. Pulse i_start high
// 5. When o_ready goes high, the transfer is complete
module Bus#(
parameter ADDR_WIDTH = 16,
parameter DATA_WIDTH = 256
) (
input i_clk,
input [ADDR_WIDTH-1:0] i_addr,
input [DATA_WIDTH-1:0] i_in,
input [0:0] i_flags, // flags.0: read(0)/write(1)
input [5:0] i_size,
input i_start, // pulsed high to start transfer
output o_ready,
output [DATA_WIDTH-1:0] o_out
);
localparam F_READ = 'b0;
localparam F_WRITE = 'b1;
localparam S_IDLE = 0;
localparam S_BUSY = 1;
reg r_status = S_IDLE;
reg r_enable = 0;
reg [5:0] r_tx_size = 0;
reg [5:0] r_byte_index = 0;
reg [7:0] r_in = 0;
reg [ADDR_WIDTH-1:0] r_mem_addr;
assign o_ready = r_byte_index == 0 || r_byte_index > r_tx_size;
always @(posedge i_clk or posedge i_start) begin
if (i_start && !r_enable) begin
r_mem_addr <= i_addr;
r_enable <= 1;
r_status <= S_BUSY;
r_tx_size <= i_size;
r_in <= i_in[0+:8];
r_byte_index <= 1; // 0 is transferring now
end else if (r_status == S_BUSY) r_status <= S_IDLE;
else if (r_enable && r_byte_index > r_tx_size) r_enable <= 0;
else if (r_enable) begin
// increment address, input next byte
r_mem_addr <= r_mem_addr + 1;
r_status <= S_BUSY;
r_in <= i_in[r_byte_index*8+:8];
r_byte_index <= r_byte_index + 1;
end
end
spMem memory (
.dout(o_out), //output [7:0] dout
.clk(i_clk), //input clk
.oce(1'b0), //input oce (unused)
.ce(r_enable), //input ce
.reset(1'b0), //input reset
.wre(i_flags[0]), //input wre (write enable)
.ad(r_mem_addr), //input [15:0] ad
.din(r_in) //input [7:0] din
);
endmodule

View file

@ -51,5 +51,11 @@
`define LI64 'h4B
`define LI64_ARGS {ARG_R, ARG_D, ARG_N, ARG_N}
// Absolute addresing memory access operations
`define LD 'h4D
`define LD_ARGS {ARG_R, ARG_R, ARG_A, ARG_H}
`define ST 'h4E
`define ST_ARGS {ARG_R, ARG_R, ARG_A, ARG_H}
// Conditional jump
`define JEQ 'h56

View file

@ -5,8 +5,10 @@ HBASM = ../hbasm
SPMEM = ../spmem.v
INPUT_FILE = inputs.txt
BUILD_DEPS = ../../src/beepo.v ../../src/instructions.v adding.v ../../src/uart_tx.v ../../src/multi7.v build/spmem_gen.v
BUILD_DEPS = ../../src/beepo.v ../../src/instructions.v adding.v ../../src/uart_tx.v ../../src/multi7.v ../../src/bus.v build/spmem_gen.v
clean:
rm -r build
${SLAPPER_BUILD}:
cargo build --manifest-path ${SLAPPER_DIR}/Cargo.toml -r
@ -34,5 +36,5 @@ wave: build/dump.vcd
assemble: build/program.bin
insert-mem: build/spmem_gen.v
synthesize: build/out
run: build/dump.vcd
synth: build/out
run: build/dump.vcd

View file

@ -22,7 +22,11 @@ module tb_adding();
initial begin
$dumpfile("build/dump.vcd");
$dumpvars(0, tb_adding, bep.r_registers[1]);
$dumpvars(0, tb_adding,
bep.r_arg_regs[0], bep.r_arg_regs[1],
bep.r_arg_regs[2], bep.r_arg_regs[3],
bep.r_registers[1]
);
end
// should probably do more granular tests

View file

@ -2,4 +2,5 @@
adding.v
../../src/uart_tx.v
../../src/multi7.v
../../src/bus.v
build/spmem_gen.v