memory: more ldm/stm

[firearm.git] / Memory.v

diff --git a/Memory.v b/Memory.v
index fb482b0c608ae0905c1de46d02ad673dfd49e0dd..3f82a5419cafbd21ec1a2e2b9d19ed81e132153d 100644 (file)
--- a/Memory.v
+++ b/Memory.v
@@ -38,15 +38,16 @@ module Memory(
        );
 
        reg [31:0] addr, raddr, next_regdata;
-       reg [3:0] next_regsel;
+       reg [3:0] next_regsel, cur_reg, prev_reg;
        reg next_writeback, next_notdone, next_inc_next;
        reg [31:0] align_s1, align_s2, align_rddata;
-       
+
        wire next_write_reg;
        wire [3:0] next_write_num;
        wire [31:0] next_write_data;
 
        reg [15:0] regs, next_regs;
+       reg started = 1'b0, next_started;
 
        reg notdone = 1'b0;
        reg inc_next = 1'b0;
@@ -62,6 +63,8 @@ module Memory(
                notdone <= next_notdone;
                inc_next <= next_inc_next;
                regs <= next_regs;
+               prev_reg <= cur_reg;
+               started <= next_started;
        end
 
        always @(*)
@@ -80,6 +83,7 @@ module Memory(
                next_inc_next = 1'b0;
                outstall = 1'b0;
                next_regs = 16'b0;
+               next_started = started;
 
                casez(insn)
                `DECODE_LDRSTR_UNDEFINED: begin end
@@ -117,68 +121,97 @@ module Memory(
                        end
                end
                `DECODE_LDMSTM: begin
-                       busaddr = {op0[31:2], 2'b0};
                        rd_req = insn[20];
                        wr_req = ~insn[20];
-                       if(inc_next) begin
+                       if(!started) begin
+                               next_regs = op1[15:0];
+                               next_started = 1'b1;
+                       end
+                       else if(inc_next) begin
+                               if(insn[21]) begin
+                                       next_write_reg = 1'b1;
+                                       next_write_num = insn[19:16];
+                                       next_write_data = op0;
+                               end
+                               next_started = 1'b0;
                        end
-                       else if(rw_wait)
+                       else if(rw_wait) begin
                                next_regs = regs;
+                               cur_reg = prev_reg;
+                       end
                        else begin
                                casez(regs)
                                16'b???????????????1: begin
+                                       cur_reg = 4'h0;
                                        next_regs = regs & 16'b1111111111111110;
                                end
                                16'b??????????????10: begin
+                                       cur_reg = 4'h1;
                                        next_regs = regs & 16'b1111111111111100;
                                end
                                16'b?????????????100: begin
+                                       cur_reg = 4'h2;
                                        next_regs = regs & 16'b1111111111111000;
                                end
                                16'b????????????1000: begin
+                                       cur_reg = 4'h3;
                                        next_regs = regs & 16'b1111111111110000;
                                end
                                16'b???????????10000: begin
+                                       cur_reg = 4'h4;
                                        next_regs = regs & 16'b1111111111100000;
                                end
                                16'b??????????100000: begin
+                                       cur_reg = 4'h5;
                                        next_regs = regs & 16'b1111111111000000;
                                end
                                16'b?????????1000000: begin
+                                       cur_reg = 4'h6;
                                        next_regs = regs & 16'b1111111110000000;
                                end
                                16'b????????10000000: begin
+                                       cur_reg = 4'h7;
                                        next_regs = regs & 16'b1111111100000000;
                                end
                                16'b???????100000000: begin
+                                       cur_reg = 4'h8;
                                        next_regs = regs & 16'b1111111000000000;
                                end
                                16'b??????1000000000: begin
+                                       cur_reg = 4'h9;
                                        next_regs = regs & 16'b1111110000000000;
                                end
                                16'b?????10000000000: begin
+                                       cur_reg = 4'hA;
                                        next_regs = regs & 16'b1111100000000000;
                                end
                                16'b????100000000000: begin
+                                       cur_reg = 4'hB;
                                        next_regs = regs & 16'b1111000000000000;
                                end
                                16'b???1000000000000: begin
+                                       cur_reg = 4'hC;
                                        next_regs = regs & 16'b1110000000000000;
                                end
                                16'b??10000000000000: begin
+                                       cur_reg = 4'hD;
                                        next_regs = regs & 16'b1100000000000000;
                                end
                                16'b?100000000000000: begin
+                                       cur_reg = 4'hE;
                                        next_regs = regs & 16'b1000000000000000;
                                end
                                16'b1000000000000000: begin
+                                       cur_reg = 4'hF;
                                        next_regs = 16'b0;
                                end
                                default: begin
+                                       cur_reg = 4'hx;
+                                       next_regs = 16'b0;
                                end
                                endcase
                                next_inc_next = next_regs == 16'b0;
-                               next_notdone = ~next_inc_next;
+                               next_notdone = ~next_inc_next | (rw_wait & insn[20] & insn[21]);
                        end
                end
                default: begin end