implement more of the bus controller

This commit is contained in:
Raphael Jacquot 2019-03-02 13:22:09 +01:00
parent 15f9b03321
commit 8ce2d2a993
6 changed files with 334 additions and 22 deletions

3
run.sh
View file

@ -13,7 +13,8 @@
iverilog -v -Wall -DSIM -o z_saturn_test.iv -s saturn_top \
saturn_top.v \
saturn_bus.v saturn_hp48gx_rom.v \
saturn_bus_controller.v
saturn_bus_controller.v saturn_debugger.v \
saturn_control_unit.v
IVERILOG_STATUS=$?
#./mask_gen_tb
echo "--------------------------------------------------------------------"

View file

@ -50,22 +50,131 @@ input wire [3:0] i_bus_nibble_in;
output wire [0:0] o_debug_cycle;
output wire [0:0] o_halt;
/**************************************************************************************************
*
* master control unit
*
*************************************************************************************************/
saturn_control_unit control_unit (
.i_clk (i_clk),
.i_reset (i_reset),
.i_phases (i_phases),
.i_phase (i_phase),
.i_cycle_ctr (i_cycle_ctr),
.i_debug_cycle (dbg_debug_cycle),
.o_program_address (ctrl_unit_prog_addr),
.o_program_data (ctrl_unit_prog_data),
.o_error (ctrl_unit_error)
);
wire [0:0] ctrl_unit_error;
wire [4:0] ctrl_unit_prog_addr;
wire [4:0] ctrl_unit_prog_data;
/**************************************************************************************************
*
* debugger module
*
*************************************************************************************************/
saturn_debugger debugger (
.i_clk (i_clk),
.i_reset (i_reset),
.i_phases (i_phases),
.i_phase (i_phase),
.i_cycle_ctr (i_cycle_ctr),
.o_debug_cycle (dbg_debug_cycle)
);
wire [0:0] dbg_debug_cycle;
assign o_debug_cycle = dbg_debug_cycle;
/**************************************************************************************************
*
* the bus controller module
*
*************************************************************************************************/
/*
* local registers
*/
reg [0:0] bus_error;
initial bus_error = 0;
/*
* program list for the bus controller
* this is used for the control unit to send the bus controller
* the list of things that need to be done for long sequences
*/
reg [4:0] bus_prog_addr;
reg [4:0] bus_program[0:31];
// this should come from the debugger
assign o_debug_cycle = 1'b0;
assign o_halt = bus_error;
always @(*) begin
$write("BUSCTRL %0d: [%d] write prog %d : %5b\n", i_phase, i_cycle_ctr, ctrl_unit_prog_addr, ctrl_unit_prog_data);
bus_program[ctrl_unit_prog_addr] = ctrl_unit_prog_data;
end
/*
* this should come from the debugger
*/
assign o_halt = bus_error || ctrl_unit_error;
initial begin
bus_error = 1'b0;
bus_prog_addr = 5'd31;
end
/*
* bus chronograms
*
* The bus works on a 4 phase system
*
*/
always @(posedge i_clk) begin
if (!o_debug_cycle) begin
case (i_phases)
4'b0001:
begin
/*
* in this phase, we can send a command or data from the processor
*/
if (bus_prog_addr != ctrl_unit_prog_addr) begin
$write("BUSCTRL %0d: [%d] %d : %5b ", i_phase, i_cycle_ctr, bus_prog_addr + 5'd1, bus_program[bus_prog_addr + 5'd1]);
if (bus_program[bus_prog_addr + 5'd1][4]) begin
$write("CMD :");
end
else $write("DATA : %h", bus_program[bus_prog_addr + 5'd1][3:0]);
$write("\n");
bus_prog_addr <= bus_prog_addr + 5'd1;
end
end
4'b0010:
begin
/*
* this phase is reserved for reading data from the bus
*/
end
4'b0100:
begin
/*
* this phase is when the instruction decoder does it's job
*/
end
4'b1000:
begin
/*
* instructions that can be handled in one clock are done here, otherwise, we start the ALU
*/
end
default: begin end // other states should not exist
endcase
end
if (i_reset) begin
bus_error <= 1'b0;
bus_error <= 1'b0;
bus_prog_addr <= 5'd31;
end
end

141
saturn_control_unit.v Normal file
View file

@ -0,0 +1,141 @@
/*
(c) Raphaël Jacquot 2019
This file is part of hp_saturn.
hp_saturn is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
any later version.
hp_saturn is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <https://www.gnu.org/licenses/>.
*/
`default_nettype none
`include "saturn_def_buscmd.v"
module saturn_control_unit (
i_clk,
i_reset,
i_phases,
i_phase,
i_cycle_ctr,
i_debug_cycle,
o_program_data,
o_program_address,
o_error
);
input wire [0:0] i_clk;
input wire [0:0] i_reset;
input wire [3:0] i_phases;
input wire [1:0] i_phase;
input wire [31:0] i_cycle_ctr;
input wire [0:0] i_debug_cycle;
output reg [4:0] o_program_data;
output reg [4:0] o_program_address;
output wire [0:0] o_error;
assign o_error = control_unit_error;
/**************************************************************************************************
*
* cpu modules go here
*
*************************************************************************************************/
/**************************************************************************************************
*
* the control unit
*
*************************************************************************************************/
reg [0:0] control_unit_error;
reg [0:0] just_reset;
reg [0:0] control_unit_ready;
reg [4:0] bus_prog_addr;
initial begin
o_program_address = 5'd31;
o_program_data = 5'd0;
control_unit_error = 1'b0;
just_reset = 1'b1;
control_unit_ready = 1'b0;
bus_prog_addr = 5'd0;
end
always @(posedge i_clk) begin
if (!i_debug_cycle && just_reset && i_phases[3]) begin
/* this happend right after reset */
`ifdef SIM
if (!i_reset)
$display("CTRL %0d: [%d] we are in the control unit", i_phase, i_cycle_ctr);
`endif
just_reset <= 1'b0;
o_program_data <= {1'b1, `BUSCMD_LOAD_PC };
`ifdef SIM
$display("CTRL %0d: [%d] pushing LOAD_PC command to pos %d", i_phase, i_cycle_ctr, bus_prog_addr);
`endif
/* push the current program pointer out,
* increment the program pointer
*/
o_program_address <= bus_prog_addr;
bus_prog_addr <= bus_prog_addr + 1;
end
/* loop to fill the initial PC value in the program */
if (!i_debug_cycle && !control_unit_ready && (bus_prog_addr != 5'b0)) begin
o_program_data <= 5'b0;
o_program_address <= bus_prog_addr;
bus_prog_addr <= bus_prog_addr + 1;
`ifdef SIM
$write("CTRL %0d: [%d] pushing ADDR[%0d] = 0", i_phase, i_cycle_ctr, bus_prog_addr);
`endif
if (bus_prog_addr == 5'd5) begin
control_unit_ready <= 1'b1;
`ifdef SIM
$write(" done");
`endif
end
`ifdef SIM
$write("\n");
`endif
end
/* this happend otherwise */
if (!i_debug_cycle && control_unit_ready) begin
`ifdef SIM
$display("CTRL %0d: [%d] starting to do things", i_phase, i_cycle_ctr);
`endif
control_unit_error <= 1'b1;
end
if (i_reset) begin
o_program_address <= 5'd31;
o_program_data <= 5'd0;
control_unit_error <= 1'b0;
just_reset <= 1'b1;
control_unit_ready <= 1'b0;
bus_prog_addr <= 5'd0;
end
end
endmodule

56
saturn_debugger.v Normal file
View file

@ -0,0 +1,56 @@
/*
(c) Raphaël Jacquot 2019
This file is part of hp_saturn.
hp_saturn is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
any later version.
hp_saturn is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <https://www.gnu.org/licenses/>.
*/
`default_nettype none
module saturn_debugger (
i_clk,
i_reset,
i_phases,
i_phase,
i_cycle_ctr,
o_debug_cycle
);
input wire [0:0] i_clk;
input wire [0:0] i_reset;
input wire [3:0] i_phases;
input wire [1:0] i_phase;
input wire [31:0] i_cycle_ctr;
output reg [0:0] o_debug_cycle;
initial begin
o_debug_cycle = 1'b0;
end
always @(posedge i_clk) begin
if (i_reset) begin
o_debug_cycle <= 1'b0;
end
end
endmodule

View file

@ -10,16 +10,16 @@
`ifndef _BUSCMD
`define _BUSCMD
`define BUSCMD_NOP 0
`define BUSCMD_ID 1
`define BUSCMD_PC_READ 2
`define BUSCMD_DP_READ 3
`define BUSCMD_PC_WRITE 4
`define BUSCMD_DP_WRITE 5
`define BUSCMD_LOAD_PC 6
`define BUSCMD_LOAD_DP 7
`define BUSCMD_CONFIGURE 8
`define BUSCMD_UNCONFIGURE 9
`define BUSCMD_RESET 15
`define BUSCMD_NOP 4'h0
`define BUSCMD_ID 4'h1
`define BUSCMD_PC_READ 4'h2
`define BUSCMD_DP_READ 4'h3
`define BUSCMD_PC_WRITE 4'h4
`define BUSCMD_DP_WRITE 4'h5
`define BUSCMD_LOAD_PC 4'h6
`define BUSCMD_LOAD_DP 4'h7
`define BUSCMD_CONFIGURE 4'h8
`define BUSCMD_UNCONFIGURE 4'h9
`define BUSCMD_RESET 4'hF
`endif

View file

@ -34,16 +34,21 @@ reg [0:0] reset;
wire [0:0] halt;
initial begin
$display("starting the simulation");
clk <= 0;
reset <= 1;
$display("TOP : starting the simulation");
clk = 0;
reset = 1;
@(posedge clk);
@(posedge clk);
@(posedge clk);
reset <= 0;
reset = 0;
$display("TOP : reset done, waiting for instructions");
@(posedge halt);
$display("TOP : instructed to stop, halt is %b", halt);
$finish;
end
always
#10 clk = (clk === 1'b0);
endmodule
`endif