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|
`include "core/uarch.sv"
module core_control
(
input logic clk,
input datapath_decode dec,
input branch_decode dec_branch,
input data_decode dec_data,
input snd_decode dec_snd,
input ldst_decode dec_ldst,
input mul_decode dec_mul,
input ptr fetch_insn_pc,
input psr_flags flags,
alu_flags,
input word rd_value_a,
rd_value_b,
q_alu,
q_shifter,
input logic c_shifter,
mem_ready,
input word mem_data_rd,
input logic mul_ready,
`ifdef VERILATOR
input word insn,
`endif
output logic stall,
branch,
writeback,
update_flags,
c_in,
output reg_num rd,
ra,
rb,
output ptr branch_target,
pc_visible,
output psr_mode reg_mode,
output psr_flags wb_alu_flags,
output alu_op alu,
output word alu_a,
alu_b,
wr_value,
output shifter_control shifter,
output logic[7:0] shifter_shift,
output ptr mem_addr,
output word mem_data_wr,
output logic mem_start,
mem_write,
mul,
mul_add,
mul_long,
mul_signed,
coproc
);
logic final_update_flags, ldst, ldst_pre, ldst_increment,
ldst_writeback, pop_valid, data_snd_is_imm, data_snd_shift_by_reg,
trivial_shift, undefined, exception, high_vectors;
logic[2:0] vector_offset;
logic[5:0] data_shift_imm;
logic[11:0] data_imm;
word saved_base, mem_offset, vector;
reg_num r_shift, popped_upper, popped_lower, popped;
reg_list mem_regs, next_regs_upper, next_regs_lower;
assign reg_mode = `MODE_SVC; //TODO
assign trivial_shift = shifter_shift == 0;
assign mem_data_wr = rd_value_b;
assign popped = ldst_increment ? popped_lower : popped_upper;
assign exception = undefined; //TODO
assign high_vectors = 0; //TODO
assign vector = {{16{high_vectors}}, 11'b0, vector_offset, 2'b00};
assign next_pc_visible = fetch_insn_pc + 2;
ctrl_cycle cycle, next_cycle;
core_control_cycles ctrl_cycles
(
.*
);
logic bubble, next_bubble;
core_control_stall ctrl_stall
(
.*
);
ptr pc /*verilator public*/, next_pc_visible;
logic issue;
core_control_issue ctrl_issue
(
.*
);
core_control_ldst_pop ctrl_ldst_pop
(
.regs(mem_regs),
.valid(pop_valid),
.next_upper(next_regs_upper),
.next_lower(next_regs_lower),
.pop_upper(popped_upper),
.pop_lower(popped_lower)
);
core_control_mux ctrl_mux
(
.*
);
logic final_writeback;
reg_num final_rd;
core_control_writeback ctrl_wb
(
.*
);
always_comb
vector_offset = 3'b001; //TODO
always_ff @(posedge clk) begin
branch <= 0;
update_flags <= 0;
wb_alu_flags <= alu_flags;
unique case(next_cycle)
ISSUE: begin
final_update_flags <= 0;
if(issue) begin
branch <= dec.branch;
branch_target <= next_pc_visible + dec_branch.offset;
alu <= dec_data.op;
ra <= dec_data.rn;
data_snd_is_imm <= dec_snd.is_imm;
data_snd_shift_by_reg <= dec_snd.shift_by_reg;
data_imm <= dec_snd.imm;
data_shift_imm <= dec_snd.shift_imm;
shifter.shr <= dec_snd.shr;
shifter.ror <= dec_snd.ror;
shifter.put_carry <= dec_snd.put_carry;
shifter.sign_extend <= dec_snd.sign_extend;
rb <= dec_snd.r;
r_shift <= dec_snd.r_shift;
c_in <= flags.c;
// TODO: dec_ldst.unprivileged/user_regs
// TODO: byte/halfword sizes
ldst <= dec.ldst;
ldst_pre <= dec_ldst.pre_indexed;
ldst_increment <= dec_ldst.increment;
ldst_writeback <= dec_ldst.writeback;
mul <= dec.mul;
mul_add <= dec_mul.add;
mul_long <= dec_mul.long_mul;
mul_signed <= dec_mul.signed_mul;
coproc <= dec.coproc;
mem_regs <= dec_ldst.regs;
mem_write <= !dec_ldst.load;
final_update_flags <= dec.update_flags;
end
update_flags <= final_update_flags;
end
RD_INDIRECT_SHIFT: begin
rb <= r_shift;
data_snd_shift_by_reg <= 0;
saved_base <= rd_value_b;
end
WITH_SHIFT: begin
c_in <= c_shifter;
saved_base <= q_shifter;
end
TRANSFER: begin
if(cycle != TRANSFER) begin
ldst <= 0;
mem_offset <= alu_b;
end
if(cycle != TRANSFER || mem_ready) begin
mem_regs <= ldst_increment ? next_regs_lower : next_regs_upper;
mem_addr <= ldst_pre ? q_alu[31:2] : alu_a[31:2];
saved_base <= q_alu;
if(pop_valid)
rb <= popped;
else
rb <= final_rd; // Viene de dec_ldst.rd
end
mem_start <= cycle != TRANSFER || (mem_ready && pop_valid);
end
BASE_WRITEBACK: ;
EXCEPTION: begin
//TODO: spsr_<mode> = cpsr
//TODO: actualizar modo
//TODO: deshabilitar IRQs/FIQs dependiendo de modo
//TODO: Considerar que data abort usa + 8, no + 4
alu <= `ALU_ADD;
data_imm <= 12'd4;
data_snd_is_imm <= 1;
final_update_flags <= 0;
end
endcase
end
initial begin
c_in = 0;
branch = 1;
branch_target = 30'd0;
data_snd_shift_by_reg = 0;
wb_alu_flags = 4'b0000;
ldst = 0;
ldst_pre = 0;
ldst_writeback = 0;
ldst_increment = 0;
mem_addr = 30'b0;
mem_write = 0;
mem_start = 0;
mem_regs = 16'b0;
mem_offset = 0;
end
endmodule
|
