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`include "core/uarch.sv"
module core_control_ldst
(
input logic clk,
rst_n,
input insn_decode dec,
input logic issue,
mem_ready,
input word rd_value_b,
q_alu,
input ctrl_cycle cycle,
next_cycle,
input word alu_a,
alu_b,
output ptr mem_addr,
output word mem_data_wr,
mem_offset,
output logic mem_start,
mem_write,
pop_valid,
ldst,
ldst_writeback,
output reg_num popped
);
logic ldst_pre, ldst_increment;
reg_num popped_upper, popped_lower;
reg_list mem_regs, next_regs_upper, next_regs_lower;
assign mem_data_wr = rd_value_b;
assign popped = ldst_increment ? popped_lower : popped_upper;
core_control_ldst_pop 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)
);
always_ff @(posedge clk or negedge rst_n)
if(!rst_n) begin
ldst <= 0;
ldst_pre <= 0;
ldst_writeback <= 0;
ldst_increment <= 0;
mem_addr <= {$bits(mem_addr){1'b0}};
mem_write <= 0;
mem_start <= 0;
mem_regs <= {$bits(mem_regs){1'b0}};
mem_offset <= 0;
end else unique case(next_cycle)
ISSUE: begin
// TODO: dec.ldst.unprivileged/user_regs
// TODO: byte/halfword sizes
if(issue)
ldst <= dec.ctrl.ldst;
ldst_pre <= dec.ldst.pre_indexed;
ldst_increment <= dec.ldst.increment;
ldst_writeback <= dec.ldst.writeback;
mem_regs <= dec.ldst.regs;
mem_write <= !dec.ldst.load;
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];
end
mem_start <= cycle != TRANSFER || (mem_ready && pop_valid);
end
endcase
endmodule
|
