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-rw-r--r--rtl/core/alu/alu.sv32
-rw-r--r--rtl/core/alu/shifter.sv42
-rw-r--r--rtl/core/arm810.sv47
-rw-r--r--rtl/core/cycles.sv158
-rw-r--r--rtl/core/decode/data.sv12
-rw-r--r--rtl/core/decode/decode.sv24
-rw-r--r--rtl/core/psr.sv5
-rw-r--r--rtl/core/shifter.sv42
-rw-r--r--rtl/core/uarch.sv15
9 files changed, 208 insertions, 169 deletions
diff --git a/rtl/core/alu/alu.sv b/rtl/core/alu/alu.sv
index 6ded727..d999164 100644
--- a/rtl/core/alu/alu.sv
+++ b/rtl/core/alu/alu.sv
@@ -3,10 +3,9 @@
module core_alu
#(parameter W=16)
(
- input alu_control ctrl,
+ input alu_op op,
input logic[W - 1:0] a,
- base,
- input logic[7:0] shift,
+ b,
input logic c_in,
output logic[W - 1:0] q,
@@ -14,22 +13,13 @@ module core_alu
output logic v_valid
);
- logic c, v, swap, sub, and_not, c_shifter, c_add, v_add;
- logic[W - 1:0] b, swap_a, swap_b, not_b, c_in_add, q_add, q_and, q_orr, q_xor;
+ logic c, v, swap, sub, and_not, c_add, v_add;
+ logic[W - 1:0] swap_a, swap_b, not_b, c_in_add, q_add, q_and, q_orr, q_xor;
assign swap_a = swap ? b : a;
assign swap_b = swap ? a : b;
assign not_b = ~b;
- core_alu_shifter #(.W(W)) shifter
- (
- .base(base),
- .shift(shift),
- .b(b),
- .c(c_shifter),
- .*
- );
-
core_alu_add #(.W(W)) op_add
(
.a(swap_a),
@@ -61,7 +51,7 @@ module core_alu
);
always_comb begin
- unique case(ctrl.op)
+ unique case(op)
`ALU_ADD, `ALU_ADC, `ALU_CMN, `ALU_CMP, `ALU_SUB, `ALU_SBC:
swap = 0;
@@ -72,7 +62,7 @@ module core_alu
swap = 1'bx;
endcase
- unique case(ctrl.op)
+ unique case(op)
`ALU_ADD, `ALU_CMN, `ALU_ADC:
sub = 0;
@@ -83,7 +73,7 @@ module core_alu
sub = 1'bx;
endcase
- unique case(ctrl.op)
+ unique case(op)
`ALU_ADD, `ALU_CMN, `ALU_CMP, `ALU_SUB, `ALU_RSB:
c_in_add = 0;
@@ -97,7 +87,7 @@ module core_alu
c_in_add = {W{1'bx}};
endcase
- unique case(ctrl.op)
+ unique case(op)
`ALU_AND, `ALU_TST:
and_not = 0;
@@ -108,7 +98,7 @@ module core_alu
and_not = 1'bx;
endcase
- unique case(ctrl.op)
+ unique case(op)
`ALU_SUB, `ALU_RSB, `ALU_ADD, `ALU_ADC, `ALU_SBC, `ALU_RSC, `ALU_CMP, `ALU_CMN:
q = q_add;
@@ -128,9 +118,9 @@ module core_alu
q = not_b;
endcase
- unique case(ctrl.op)
+ unique case(op)
`ALU_AND, `ALU_EOR, `ALU_TST, `ALU_TEQ, `ALU_ORR, `ALU_MOV, `ALU_BIC, `ALU_MVN: begin
- c = c_shifter;
+ c = c_in;
v = 1'bx;
v_valid = 0;
end
diff --git a/rtl/core/alu/shifter.sv b/rtl/core/alu/shifter.sv
deleted file mode 100644
index 1f99e99..0000000
--- a/rtl/core/alu/shifter.sv
+++ /dev/null
@@ -1,42 +0,0 @@
-`include "core/uarch.sv"
-
-module core_alu_shifter
-#(parameter W=16)
-(
- input alu_control ctrl,
- input logic[W - 1:0] base,
- input logic[7:0] shift,
- input logic c_in,
-
- output logic[W - 1:0] b,
- output logic c
-);
-
- localparam LOG = $clog2(W);
-
- logic[W - 1:0] b_no_c, b_shl, b_shr, b_ror;
- logic[W:0] sign_mask;
- logic c_shl, c_shr, c_ror;
-
- assign sign_mask = {(W + 1){ctrl.sign_extend & base[W - 1]}};
- assign {c_shl, b_shl} = {c_in, base} << shift;
- assign {b_shr, c_shr} = {base, c_in} >> shift | ~(sign_mask >> shift);
-
- logic ror_cycle;
- logic[LOG - 1:0] ror_shift;
- logic[2 * W:0] ror_out;
-
- assign ror_shift = shift[LOG - 1:0];
- assign ror_cycle = |shift[7:LOG] & ~|ror_shift;
- assign ror_out = {base, base, c_in} >> {ror_cycle, ror_shift};
- assign {b_ror, c_ror} = ror_out[W:0];
-
- always_comb
- if(ctrl.ror)
- {c, b} = {c_ror, b_ror};
- else if(ctrl.shr)
- {c, b} = {c_shr, b_shr[W - 1] | (ctrl.put_carry & c_in), b_shr[W - 2:0]};
- else
- {c, b} = {c_shl, b_shl};
-
-endmodule
diff --git a/rtl/core/arm810.sv b/rtl/core/arm810.sv
index 8ea6ed3..a8e197b 100644
--- a/rtl/core/arm810.sv
+++ b/rtl/core/arm810.sv
@@ -14,7 +14,7 @@ module arm810
logic stall, prefetch_flush;
word insn;
- ptr fetch_insn_pc, pc, pc_visible;
+ ptr fetch_insn_pc;
core_fetch #(.PREFETCH_ORDER(2)) fetch
(
@@ -31,7 +31,7 @@ module arm810
logic dec_execute, dec_undefined, dec_writeback, dec_branch, dec_update_flags;
ptr dec_branch_offset;
- alu_decode dec_alu;
+ data_decode dec_data;
core_decode decode
(
@@ -41,26 +41,28 @@ module arm810
.branch(dec_branch),
.update_flags(dec_update_flags),
.branch_offset(dec_branch_offset),
- .alu(dec_alu),
+ .data_ctrl(dec_data),
.*
);
reg_num rd, ra, rb;
- logic explicit_branch, writeback, update_flags;
- ptr branch_target;
+ logic explicit_branch, writeback, update_flags, c_in;
+ ptr branch_target, pc_visible;
psr_mode reg_mode;
- alu_control alu_ctrl;
- word alu_base;
- logic[7:0] alu_shift;
+ alu_op alu_ctrl;
+ shifter_control shifter_ctrl;
+ word alu_b, wr_value;
+ logic[7:0] shifter_shift;
core_cycles cycles
(
.branch(explicit_branch),
.alu(alu_ctrl),
+ .shifter(shifter_ctrl),
.*
);
- psr_flags flags;
+ psr_flags flags, next_flags;
core_psr psr
(
@@ -68,7 +70,7 @@ module arm810
);
logic wr_pc;
- word wr_value, rd_value_a, rd_value_b;
+ word rd_value_a, rd_value_b;
core_regs regs
(
@@ -84,17 +86,30 @@ module arm810
psr_flags alu_flags;
logic alu_v_valid;
+ word q_alu;
core_alu #(.W(32)) alu
(
- .ctrl(alu_ctrl),
+ .op(alu_ctrl),
.a(rd_value_a),
- .base(alu_base),
- .shift(alu_shift),
- .c_in(flags.c),
- .q(wr_value),
+ .b(alu_b),
+ .q(q_alu),
.nzcv(alu_flags),
- .v_valid(alu_v_valid)
+ .v_valid(alu_v_valid),
+ .*
+ );
+
+ word q_shifter;
+ logic c_shifter;
+
+ core_shifter #(.W(32)) shifter
+ (
+ .ctrl(shifter_ctrl),
+ .base(alu_b),
+ .shift(shifter_shift),
+ .c_in(flags.c),
+ .q(q_shifter),
+ .c(c_shifter)
);
endmodule
diff --git a/rtl/core/cycles.sv b/rtl/core/cycles.sv
index 8945bc2..c32bff0 100644
--- a/rtl/core/cycles.sv
+++ b/rtl/core/cycles.sv
@@ -2,77 +2,102 @@
module core_cycles
(
- input logic clk,
- dec_execute,
- dec_branch,
- dec_writeback,
- dec_update_flags,
- input ptr dec_branch_offset,
- input alu_decode dec_alu,
- input ptr fetch_insn_pc,
- input word rd_value_b,
-
- output logic stall,
- branch,
- writeback,
- update_flags,
- output reg_num rd,
- ra,
- rb,
- output ptr branch_target,
- pc,
- pc_visible,
- output psr_mode reg_mode,
- output alu_control alu,
- output word alu_base,
- output logic[7:0] alu_shift
+ input logic clk,
+ dec_execute,
+ dec_branch,
+ dec_writeback,
+ dec_update_flags,
+ input ptr dec_branch_offset,
+ input data_decode dec_data,
+ input ptr fetch_insn_pc,
+ input psr_flags next_flags,
+ input word rd_value_b,
+ q_alu,
+ q_shifter,
+ input logic c_shifter,
+
+ 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 alu_op alu,
+ output word alu_b,
+ wr_value,
+ output shifter_control shifter,
+ output logic[7:0] shifter_shift
);
enum
{
EXECUTE,
- RD_SHIFT
+ RD_INDIRECT_SHIFT,
+ WITH_SHIFT
} cycle, next_cycle;
- logic final_writeback, data_snd_is_imm, data_snd_shift_by_reg;
+ logic bubble, final_writeback, data_snd_is_imm, data_snd_shift_by_reg, trivial_shift;
logic[5:0] data_shift_imm;
logic[7:0] data_imm;
- logic bubble;
word saved_base;
- reg_num r_shift;
+ reg_num r_shift, final_rd;
+ ptr pc;
assign stall = (next_cycle != EXECUTE) | bubble;
assign pc_visible = pc + 2;
assign reg_mode = `MODE_SVC; //TODO
always_comb begin
+ unique case(cycle)
+ RD_INDIRECT_SHIFT: shifter_shift = rd_value_b[7:0];
+ default: shifter_shift = {2'b00, data_shift_imm};
+ endcase
+
+ trivial_shift = 1;
+ if(final_writeback & (shifter.shl | shifter.shr | shifter.ror))
+ trivial_shift = shifter_shift == 0;
+
next_cycle = EXECUTE;
- if((cycle == EXECUTE) & data_snd_shift_by_reg)
- next_cycle = RD_SHIFT;
+
+ unique case(cycle)
+ EXECUTE:
+ if(data_snd_shift_by_reg)
+ next_cycle = RD_INDIRECT_SHIFT;
+ else if(~trivial_shift)
+ next_cycle = WITH_SHIFT;
+
+ RD_INDIRECT_SHIFT:
+ if(~trivial_shift)
+ next_cycle = WITH_SHIFT;
+
+ default: ;
+ endcase
if(bubble)
next_cycle = EXECUTE;
unique case(cycle)
- RD_SHIFT:
- alu_base = saved_base;
-
- default:
+ EXECUTE:
if(data_snd_is_imm)
- alu_base = {{24{1'b0}}, data_imm};
+ alu_b = {{24{1'b0}}, data_imm};
else
- alu_base = rd_value_b;
- endcase
+ alu_b = rd_value_b;
- unique case(cycle)
- RD_SHIFT: alu_shift = rd_value_b[7:0];
- default: alu_shift = {2'b00, data_shift_imm};
+ RD_INDIRECT_SHIFT, WITH_SHIFT:
+ alu_b = saved_base;
endcase
end
always_ff @(posedge clk) begin
cycle <= next_cycle;
bubble <= 0;
+ writeback <= 0;
+ wr_value <= q_alu;
unique case(next_cycle)
EXECUTE: begin
@@ -84,40 +109,47 @@ module core_cycles
if(dec_execute & ~bubble) begin
bubble <=
(dec_update_flags & update_flags)
- | (final_writeback & ((rd == dec_alu.rn) | (rd == dec_alu.r_snd)));
+ | (final_writeback & ((rd == dec_data.rn) | (rd == dec_data.r_snd)));
branch <= dec_branch;
- final_writeback <= dec_writeback;
update_flags <= dec_update_flags;
branch_target <= pc_visible + dec_branch_offset;
- data_snd_is_imm <= dec_alu.snd_is_imm;
- data_snd_shift_by_reg <= dec_alu.snd_shift_by_reg;
- data_imm <= dec_alu.imm;
- data_shift_imm <= dec_alu.shift_imm;
-
- alu.op <= dec_alu.op;
- alu.shl <= dec_alu.shl;
- alu.shr <= dec_alu.shr;
- alu.ror <= dec_alu.ror;
- alu.put_carry <= dec_alu.put_carry;
- alu.sign_extend <= dec_alu.sign_extend;
-
- rd <= dec_alu.rd;
- ra <= dec_alu.rn;
- rb <= dec_alu.r_snd;
- r_shift <= dec_alu.r_shift;
+ data_snd_is_imm <= dec_data.snd_is_imm;
+ data_snd_shift_by_reg <= dec_data.snd_shift_by_reg;
+ data_imm <= dec_data.imm;
+ data_shift_imm <= dec_data.shift_imm;
+
+ alu <= dec_data.op;
+ shifter.shl <= dec_data.shl;
+ shifter.shr <= dec_data.shr;
+ shifter.ror <= dec_data.ror;
+ shifter.put_carry <= dec_data.put_carry;
+ shifter.sign_extend <= dec_data.sign_extend;
+
+ ra <= dec_data.rn;
+ rb <= dec_data.r_snd;
+ r_shift <= dec_data.r_shift;
+ c_in <= next_flags.c;
+
+ final_rd <= dec_data.rd;
+ final_writeback <= dec_writeback;
end
writeback <= final_writeback;
+ rd <= final_rd;
pc <= fetch_insn_pc;
end
- RD_SHIFT: begin
+ RD_INDIRECT_SHIFT: begin
rb <= r_shift;
data_snd_shift_by_reg <= 0;
saved_base <= rd_value_b;
- writeback <= 0;
+ end
+
+ WITH_SHIFT: begin
+ c_in <= c_shifter;
+ saved_base <= q_shifter;
end
endcase
end
@@ -127,10 +159,14 @@ module core_cycles
bubble = 0;
pc = 0;
+ c_in = 0;
branch = 1;
writeback = 0;
- data_snd_shift_by_reg = 0;
branch_target = 30'd0;
+ data_snd_shift_by_reg = 0;
+
+ final_rd = 0;
+ final_writeback = 0;
end
endmodule
diff --git a/rtl/core/decode/data.sv b/rtl/core/decode/data.sv
index 4dc51a4..a649440 100644
--- a/rtl/core/decode/data.sv
+++ b/rtl/core/decode/data.sv
@@ -3,13 +3,13 @@
module core_decode_data
(
- input word insn,
+ input word insn,
- output alu_decode decode,
- output logic writeback,
- update_flags,
- restore_spsr,
- undefined
+ output data_decode decode,
+ output logic writeback,
+ update_flags,
+ restore_spsr,
+ undefined
);
alu_op op;
diff --git a/rtl/core/decode/decode.sv b/rtl/core/decode/decode.sv
index af80135..f7d7be8 100644
--- a/rtl/core/decode/decode.sv
+++ b/rtl/core/decode/decode.sv
@@ -6,13 +6,13 @@ module core_decode
input word insn,
input psr_flags flags,
- output logic execute,
- undefined,
- writeback,
- update_flags,
- branch,
- output ptr branch_offset,
- output alu_decode alu
+ output logic execute,
+ undefined,
+ writeback,
+ update_flags,
+ branch,
+ output ptr branch_offset,
+ output data_decode data_ctrl
);
logic cond_undefined;
@@ -38,11 +38,11 @@ module core_decode
logic restore_spsr;
logic data_writeback, data_update_flags, data_undefined;
- alu_decode data_alu;
+ data_decode data;
core_decode_data group_data
(
- .decode(data_alu),
+ .decode(data),
.writeback(data_writeback),
.update_flags(data_update_flags),
.undefined(data_undefined),
@@ -55,20 +55,20 @@ module core_decode
branch = 0;
writeback = 0;
update_flags = 0;
- alu = {($bits(alu)){1'bx}};
+ data_ctrl = {($bits(data_ctrl)){1'bx}};
priority casez(insn `FIELD_OP)
`GROUP_B: begin
branch = 1;
if(branch_link) begin
- alu.rd = `R14;
+ data_ctrl.rd = `R14;
writeback = 1;
//TODO: Valor de LR
end
end
`GROUP_ALU: begin
- alu = data_alu;
+ data_ctrl = data;
writeback = data_writeback;
update_flags = data_update_flags;
undefined = undefined | data_undefined;
diff --git a/rtl/core/psr.sv b/rtl/core/psr.sv
index bc682c1..2c0d48f 100644
--- a/rtl/core/psr.sv
+++ b/rtl/core/psr.sv
@@ -7,11 +7,10 @@ module core_psr
alu_v_valid,
input psr_flags alu_flags,
- output psr_flags flags
+ output psr_flags flags,
+ next_flags
);
- psr_flags next_flags;
-
always_comb begin
next_flags = flags;
diff --git a/rtl/core/shifter.sv b/rtl/core/shifter.sv
new file mode 100644
index 0000000..994e76c
--- /dev/null
+++ b/rtl/core/shifter.sv
@@ -0,0 +1,42 @@
+`include "core/uarch.sv"
+
+module core_shifter
+#(parameter W=16)
+(
+ input shifter_control ctrl,
+ input logic[W - 1:0] base,
+ input logic[7:0] shift,
+ input logic c_in,
+
+ output logic[W - 1:0] q,
+ output logic c
+);
+
+ localparam LOG = $clog2(W);
+
+ logic[W - 1:0] q_no_c, q_shl, q_shr, q_ror;
+ logic[W:0] sign_mask;
+ logic c_shl, c_shr, c_ror;
+
+ assign sign_mask = {(W + 1){ctrl.sign_extend & base[W - 1]}};
+ assign {c_shl, q_shl} = {c_in, base} << shift;
+ assign {q_shr, c_shr} = {base, c_in} >> shift | ~(sign_mask >> shift);
+
+ logic ror_cycle;
+ logic[LOG - 1:0] ror_shift;
+ logic[2 * W:0] ror_out;
+
+ assign ror_shift = shift[LOG - 1:0];
+ assign ror_cycle = |shift[7:LOG] & ~|ror_shift;
+ assign ror_out = {base, base, c_in} >> {ror_cycle, ror_shift};
+ assign {q_ror, c_ror} = ror_out[W:0];
+
+ always_comb
+ if(ctrl.ror)
+ {c, q} = {c_ror, q_ror};
+ else if(ctrl.shr)
+ {c, q} = {c_shr, q_shr[W - 1] | (ctrl.put_carry & c_in), q_shr[W - 2:0]};
+ else
+ {c, q} = {c_shl, q_shl};
+
+endmodule
diff --git a/rtl/core/uarch.sv b/rtl/core/uarch.sv
index c382cba..0c5bc84 100644
--- a/rtl/core/uarch.sv
+++ b/rtl/core/uarch.sv
@@ -72,16 +72,15 @@ typedef struct packed
sign_extend;
logic[7:0] imm;
logic[5:0] shift_imm;
-} alu_decode;
+} data_decode;
typedef struct packed
{
- alu_op op;
- logic shl,
- shr,
- ror,
- put_carry,
- sign_extend;
-} alu_control;
+ logic shl,
+ shr,
+ ror,
+ put_carry,
+ sign_extend;
+} shifter_control;
`endif
generated by cgit v1.2.3 (git 2.25.1) at 2026-04-17 11:54:30 +0000