Memory: Add work-around for Xilinx bug in MULT.

diff --git a/Memory.v b/Memory.v
index 63dfb9bd0a376c57b3df59e0bb1c5bad1e2661b4..1dad548ca37102323ef0b7d845a78dc1f490a8f6 100644 (file)
--- a/Memory.v
+++ b/Memory.v
@@ -161,7 +161,10 @@ module Memory(
                        end
                        endcase
                end
-               `DECODE_ALU_MULT: begin end
+               `DECODE_ALU_MULT: begin
+                       outstall = 1'b0;        /* XXX work around for Xilinx bug */
+                       next_lsrh_state = lsrh_state;
+               end
                `DECODE_ALU_HDATA_REG,
                `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
                        case(lsrh_state)
@@ -346,7 +349,13 @@ module Memory(
                        default: begin end
                        endcase
                end
-               `DECODE_ALU_MULT: begin end
+               `DECODE_ALU_MULT: begin
+                       next_write_reg = write_reg;     /* XXX workaround for ISE 10.1 bug */
+                       next_write_num = write_num;
+                       next_write_data = write_data;
+                       next_outcpsr = lsm_state == 4'b0010 ? outcpsr : cpsr;
+                       next_outcpsrup = cpsrup;
+               end
                `DECODE_ALU_HDATA_REG,
                `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
                        next_write_reg = 1'bx;
@@ -466,7 +475,12 @@ module Memory(
                        default: begin end
                        endcase
                end
-               `DECODE_ALU_MULT: begin end
+               `DECODE_ALU_MULT: begin
+                       rd_req = 1'b0;  /* XXX workaround for Xilinx bug */
+                       wr_req = 1'b0;
+                       offset = prev_offset;
+                       addr = prevaddr;
+               end
                `DECODE_ALU_HDATA_REG,
                `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
                        addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */
@@ -710,7 +724,9 @@ module Memory(
                        default: begin end
                        endcase
                end
-               `DECODE_ALU_MULT: begin end
+               `DECODE_ALU_MULT: begin
+                       next_outbubble = inbubble;      /* XXX workaround for Xilinx bug */
+               end
                `DECODE_ALU_HDATA_REG,
                `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
                        next_outbubble = rw_wait;