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passes quick test: beq, blt, bltu

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This commit is contained in:
Brendan Haines 2020-11-09 20:01:25 -07:00
parent 06d0e07c61
commit 6e0d9c96a1
3 changed files with 100 additions and 35 deletions
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27
hdl/core.v
View File

@ -91,7 +91,8 @@ reg r_ex_load, r_mem_load;
reg [31:0] r_mem_wdata, r_wb_wdata;
reg r_id_valid=0, r_ex_valid=0, r_mem_valid=0, r_wb_valid=0;
reg r_ex_branch_pol;
reg r_ex_branch;
reg r_ex_branch, r_mem_branch, r_wb_branch;
reg [31:0] r_ex_immed_btype;
// IF
reg s_if_stall = 0;
@ -101,12 +102,10 @@ reg [31:0] s_if_inst;
always @(*) begin
s_if_stall = s_id_stall;
if (s_ex_take_branch && r_ex_valid) begin
s_if_next_pc = s_ex_alu_out;
// s_if_stall = 1'b1;
if (s_ex_take_branch) begin
s_if_next_pc = s_ex_branch_addr;
end else begin
s_if_next_pc = r_if_pc + 4;
// s_if_stall = 1'b0;
end
mem_inst_addr = r_if_pc;
@ -289,7 +288,7 @@ always @(*) begin
endcase
s_id_stall = s_ex_stall ||
(r_ex_valid &&
(r_ex_valid && (s_ex_take_branch == 0) &&
(((r_ex_rd == s_id_rs1) && (s_id_rs1 != 0)) ||
((r_ex_rd == s_id_rs2) && (s_id_rs2 != 0)))) ||
(r_mem_valid &&
@ -310,9 +309,9 @@ reg s_ex_stall = 0;
reg [31:0] s_ex_data1, s_ex_data2;
reg [31:0] s_ex_alu_out;
reg s_ex_alu_zero;
reg [31:0] s_ex_ra;
reg [31:0] s_ex_wdata;
reg s_ex_take_branch;
reg [31:0] s_ex_branch_addr;
always @(*) begin
s_ex_stall = s_mem_stall;
@ -358,14 +357,13 @@ always @(*) begin
endcase
s_ex_alu_zero = (s_ex_alu_out == 0);
s_ex_ra = r_ex_pc + 4;
// s_ex_branch_addr = r_ex_pc +
// TODO: determine and go to branch address (pc+offset)
s_ex_take_branch = r_ex_jump || (r_ex_branch && (s_ex_alu_zero ^ r_ex_branch_pol));
s_ex_take_branch = r_ex_valid && (r_ex_jump || (r_ex_branch && (s_ex_alu_zero ^ r_ex_branch_pol)));
if (r_ex_jump) begin
s_ex_wdata = s_ex_ra;
s_ex_wdata = r_ex_pc + 4;
s_ex_branch_addr = s_ex_alu_out;
end else begin
s_ex_wdata = s_ex_alu_out;
s_ex_branch_addr = r_ex_pc + r_ex_immed_btype;
end
end
@ -402,7 +400,7 @@ always @(*) begin
s_wb_data = r_wb_wdata;
// FIXME: always writes!!!
s_wb_write = 1; //!s_wb_stall;
s_wb_write = (r_wb_branch == 0);
end
// SYS
@ -474,6 +472,7 @@ always @(posedge clk) begin: pipeline_update
r_ex_load <= s_id_load;
r_ex_valid <= r_id_valid && ~(s_ex_take_branch && r_ex_valid) && ~(s_id_stall && r_id_valid);
r_ex_branch_pol <= s_id_branch_pol;
r_ex_immed_btype <= s_id_immed_btype;
end
@ -490,6 +489,7 @@ always @(posedge clk) begin: pipeline_update
r_mem_load <= r_ex_load;
r_mem_wdata <= s_ex_wdata;
r_mem_valid <= r_ex_valid;
r_mem_branch <= r_ex_branch;
end
// WB
@ -500,6 +500,7 @@ always @(posedge clk) begin: pipeline_update
r_wb_alu_out <= r_mem_alu_out;
r_wb_wdata <= r_mem_wdata;
r_wb_valid <= r_mem_valid;
r_wb_branch <= r_mem_branch;
end
// Register File

39
sim/core_tb.wcfg
View File

@ -255,6 +255,31 @@
<obj_property name="ObjectShortName">s_id_rs2[4:0]</obj_property>
<obj_property name="Radix">UNSIGNEDDECRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_immed_itype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_immed_itype[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_immed_itype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_immed_stype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_immed_stype[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_immed_stype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_immed_utype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_immed_utype[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_immed_utype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_immed_btype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_immed_btype[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_immed_btype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_immed_jtype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_immed_jtype[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_immed_jtype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_id_s1" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_id_s1[31:0]</obj_property>
<obj_property name="ObjectShortName">s_id_s1[31:0]</obj_property>
@ -361,6 +386,16 @@
<obj_property name="ElementShortName">s_ex_take_branch</obj_property>
<obj_property name="ObjectShortName">s_ex_take_branch</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/r_ex_immed_btype" type="array" db_ref_id="1">
<obj_property name="ElementShortName">r_ex_immed_btype[31:0]</obj_property>
<obj_property name="ObjectShortName">r_ex_immed_btype[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_ex_branch_addr" type="array" db_ref_id="1">
<obj_property name="ElementShortName">s_ex_branch_addr[31:0]</obj_property>
<obj_property name="ObjectShortName">s_ex_branch_addr[31:0]</obj_property>
<obj_property name="Radix">HEXRADIX</obj_property>
</wvobject>
</wvobject>
<wvobject fp_name="group7" type="group">
<obj_property name="label">MEM</obj_property>
@ -405,10 +440,6 @@
<obj_property name="ElementShortName">r_wb_valid</obj_property>
<obj_property name="ObjectShortName">r_wb_valid</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/s_wb_stall" type="logic" db_ref_id="1">
<obj_property name="ElementShortName">s_wb_stall</obj_property>
<obj_property name="ObjectShortName">s_wb_stall</obj_property>
</wvobject>
<wvobject fp_name="/core_tb/dut/r_wb_pc" type="array" db_ref_id="1">
<obj_property name="ElementShortName">r_wb_pc[31:0]</obj_property>
<obj_property name="ObjectShortName">r_wb_pc[31:0]</obj_property>

69
test/test.S
View File

@ -137,26 +137,49 @@ _start:
# jal
jal x1, test_jalr
# test1:
# # TODO: redo these tests because my nop test messed it up
# # beq
# addi x30, x0, 1 # x30 = 1
# addi x9, x8, 0 # x9 == x8
# bne x0, x0, fail # 0 == 0
# bne x9, x8, fail # x9 == x8
# bne x7, x8, test2 # x7 != x8
# j fail
test1:
# beq
addi x30, x0, 1 # x30 = 1
addi x9, x8, 0 # x9 = 0xffffff00
bne x0, x0, fail # 0 == 0
bne x9, x8, fail # x9 == x8
bne x7, x8, test2 # x7 != x8
j fail
# test2:
# # beq
# addi x30, x0, 2 # x30 = 2
# beq x0, x8, fail # 0 != x8
# beq x7, x8, fail # x7 != x8
# beq x8, x9, test3 # x8 == x9
# j fail
test2:
# beq
addi x30, x0, 2 # x30 = 2
beq x0, x8, fail # 0 != x8
beq x7, x8, fail # x7 != x8
beq x8, x9, test3 # x8 == x9
j fail
# test3:
test3:
#blt
addi x30, x0, 3 # x30 = 3
blt x8, x9, fail # x8 == x9
blt x7, x8, fail # x7 > x8
blt x30, x8, fail # x30 > x8
blt x8, x7, test4 # x8 < x7
j fail
test4:
#bltu
addi x30, x0, 4 # x30 = 4
bltu x8, x9, fail # x8 == x9
bltu x8, x7, fail # x8 < x7
bltu x30, x8, test5 # x30 < x8 unsigned
test5:
addi x30, x0, 5 # x30 = 5
# set registers to known values before loop
addi x2, x0, 1 # x1 = 1
addi x3, x0, 1 # x1 = 1
addi x4, x0, 1 # x1 = 1
addi x5, x0, 1 # x1 = 1
addi x6, x0, 1 # x1 = 1
# counter and infinite loop
addi x31, x0, 1 # x1 = 1
@ -182,7 +205,17 @@ test_jalr:
jalr x0, x1, 0 # return
fail:
jal x0, fail # loop forever
# set some registers to make it blatantly obvious an error occurred
addi x1, x0, 0x7ff # x1 = 0x1111
addi x2, x0, 0x7ff # x1 = 0x1111
addi x3, x0, 0x7ff # x1 = 0x1111
addi x4, x0, 0x7ff # x1 = 0x1111
addi x5, x0, 0x7ff # x1 = 0x1111
addi x6, x0, 0x7ff # x1 = 0x1111
addi x7, x0, 0x7ff # x1 = 0x1111
addi x8, x0, 0x7ff # x1 = 0x1111
addi x9, x0, 0x7ff # x1 = 0x1111
j fail # loop forever
nop
nop
nop