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picorv32
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Fixed the nontrivial compressed ISA bug found by tracecmp2

This commit is contained in:
Clifford Wolf 2016-09-16 13:15:21 +02:00
parent 197b6ffe2b
commit 4101cfe810
1 changed files with 15 additions and 3 deletions
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18
picorv32.v
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@ -296,8 +296,9 @@ module picorv32 #(
reg mem_do_rdata;
reg mem_do_wdata;
reg mem_la_secondword;
reg mem_la_secondword, mem_la_firstword_reg, last_mem_valid;
wire mem_la_firstword = COMPRESSED_ISA && (mem_do_prefetch || mem_do_rinst) && next_pc[1] && !mem_la_secondword;
wire mem_la_firstword_xfer = COMPRESSED_ISA && mem_xfer && (!last_mem_valid ? mem_la_firstword : mem_la_firstword_reg);
reg prefetched_high_word;
reg clear_prefetched_high_word;
@ -316,7 +317,7 @@ module picorv32 #(
assign mem_la_write = resetn && !mem_state && mem_do_wdata;
assign mem_la_read = resetn && ((!mem_la_use_prefetched_high_word && !mem_state && (mem_do_rinst || mem_do_prefetch || mem_do_rdata)) ||
(COMPRESSED_ISA && mem_xfer && mem_la_firstword && !mem_la_secondword && &mem_rdata_latched[1:0]));
assign mem_la_addr = (mem_do_prefetch || mem_do_rinst) ? {next_pc[31:2] + (mem_xfer && mem_la_firstword), 2'b00} : {reg_op1[31:2], 2'b00};
assign mem_la_addr = (mem_do_prefetch || mem_do_rinst) ? {next_pc[31:2] + mem_la_firstword_xfer, 2'b00} : {reg_op1[31:2], 2'b00};
assign mem_rdata_latched_noshuffle = (mem_xfer || LATCHED_MEM_RDATA) ? mem_rdata : mem_rdata_q;
@ -324,6 +325,17 @@ module picorv32 #(
COMPRESSED_ISA && mem_la_secondword ? {mem_rdata_latched_noshuffle[15:0], mem_16bit_buffer} :
COMPRESSED_ISA && mem_la_firstword ? {16'bx, mem_rdata_latched_noshuffle[31:16]} : mem_rdata_latched_noshuffle;
always @(posedge clk) begin
if (!resetn) begin
mem_la_firstword_reg <= 0;
last_mem_valid <= 0;
end else begin
if (!last_mem_valid)
mem_la_firstword_reg <= mem_la_firstword;
last_mem_valid <= mem_valid && !mem_ready;
end
end
always @* begin
(* full_case *)
case (mem_wordsize)
@ -524,7 +536,7 @@ module picorv32 #(
`assert(mem_valid == !mem_la_use_prefetched_high_word);
`assert(mem_instr == (mem_do_prefetch || mem_do_rinst));
if (mem_xfer) begin
if (COMPRESSED_ISA && mem_la_read) begin
if (COMPRESSED_ISA && mem_la_read && (!last_mem_valid ? mem_la_firstword : mem_la_firstword_reg)) begin
mem_valid <= 1;
mem_la_secondword <= 1;
if (!mem_la_use_prefetched_high_word)