Merge pull request #11 from kitune-san/dma-ram-refresh

Dma ram refresh
spark2k06 · Jun 24, 2022 · f205e8a · f205e8a
2 parents bac15f3 + e6a6c3e
commit f205e8a
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Showing 5 changed files with 54 additions and 9 deletions.
diff --git a/rtl/KFPC-XT/HDL/Chipset.sv b/rtl/KFPC-XT/HDL/Chipset.sv
@@ -124,6 +124,24 @@ module CHIPSET (
     logic           data_bus_out_from_chipset;
     logic           internal_data_bus_direction;
 
+    logic           prev_timer_count_1;
+    logic           DRQ0;
+
+    always_ff @(negedge clock) begin
+        prev_timer_count_1 <= timer_counter_out[1];
+    end
+
+    always_ff @(negedge clock, posedge reset) begin
+        if (reset)
+            DRQ0 <= 1'b0;
+        else if (~dma_acknowledge_n[0])
+            DRQ0 <= 1'b0;
+        else if (~prev_timer_count_1 & timer_counter_out[1])
+            DRQ0 <= 1'b1;
+        else
+            DRQ0 <= DRQ0;
+    end
+
     READY u_READY (
         .clock                              (clock),
         .reset                              (reset),
@@ -170,7 +188,7 @@ module CHIPSET (
         .memory_write_n                     (memory_write_n),
         .memory_write_n_ext                 (memory_write_n_ext),
         .memory_write_n_direction           (memory_write_n_direction),
-        .dma_request                        (dma_request),
+        .dma_request                        ({dma_request[3:1], DRQ0}),
         .dma_acknowledge_n                  (dma_acknowledge_n),
         .address_enable_n                   (address_enable_n),
         .terminal_count_n                   (terminal_count_n)

diff --git a/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237.sv b/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237.sv
@@ -46,6 +46,7 @@ module KF8237 (
     logic   [3:0]   write_base_and_current_address;
     logic   [3:0]   write_base_and_current_word_count;
     logic           clear_byte_pointer;
+    logic           set_byte_pointer;
     logic           master_clear;
     logic           clear_mask_register;
     logic           read_temporary_register;
@@ -78,6 +79,7 @@ module KF8237 (
         .write_base_and_current_word_count  (write_base_and_current_word_count),
         // -- software command
         .clear_byte_pointer                 (clear_byte_pointer),
+        .set_byte_pointer                   (set_byte_pointer),
         .master_clear                       (master_clear),
         .clear_mask_register                (clear_mask_register),
         // -- read
@@ -150,6 +152,7 @@ module KF8237 (
         .write_base_and_current_word_count  (write_base_and_current_word_count),
         // -- software command
         .clear_byte_pointer                 (clear_byte_pointer),
+        .set_byte_pointer                   (set_byte_pointer),
         .master_clear                       (master_clear),
         // -- read
         .read_current_address               (read_current_address),

diff --git a/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Address_And_Count_Registers.sv b/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Address_And_Count_Registers.sv
@@ -19,6 +19,7 @@ module KF8237_Address_And_Count_Registers (
     input   logic   [3:0]   write_base_and_current_word_count,
     // -- software command
     input   logic           clear_byte_pointer,
+    input   logic           set_byte_pointer,
     input   logic           master_clear,
     // -- read
     input   logic   [3:0]   read_current_address,
@@ -74,6 +75,8 @@ module KF8237_Address_And_Count_Registers (
             byte_pointer <= 1'b0;
         else if ((master_clear) || (clear_byte_pointer))
             byte_pointer <= 1'b0;
+        else if (set_byte_pointer)
+            byte_pointer <= 1'b1;
         else if (update_byte_pointer)
              if (byte_pointer)
                  byte_pointer <= 1'b0;

diff --git a/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Bus_Control_Logic.sv b/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Bus_Control_Logic.sv
@@ -30,6 +30,7 @@ module KF8237_Bus_Control_Logic (
     output  logic   [3:0]   write_base_and_current_word_count,
     // -- software command
     output  logic           clear_byte_pointer,
+    output  logic           set_byte_pointer,
     output  logic           master_clear,
     output  logic           clear_mask_register,
     // -- read
@@ -93,6 +94,7 @@ module KF8237_Bus_Control_Logic (
 
     // Generate software command
     assign  clear_byte_pointer                      = write_flag & (stable_address == 4'b1100);
+    assign  set_byte_pointer                        = read_flag  & (stable_address == 4'b1100);
     assign  master_clear                            = write_flag & (stable_address == 4'b1101);
     assign  clear_mask_register                     = write_flag & (stable_address == 4'b1110);
 

diff --git a/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Timing_And_Control.sv b/rtl/KFPC-XT/HDL/KF8237/HDL/KF8237_Timing_And_Control.sv
@@ -86,8 +86,10 @@ module KF8237_Timing_And_Control (
     logic   [1:0]   dma_select;
     logic   [3:0]   dma_acknowledge_ff;
     logic           terminal_count;
+    logic           terminal_count_internal;
     logic           reoutput_high_address;
     logic           external_end_of_process;
+    logic           prev_read_status_register;
 
     //
     // Command Register
@@ -516,16 +518,26 @@ module KF8237_Timing_And_Control (
     // Terminal Count Signal (NOTE:Posedge)
     //
     always_ff @(posedge clock, posedge reset) begin
-        if (reset)
+        if (reset) begin
             terminal_count <= 1'b0;
-        else if (master_clear)
+            terminal_count_internal <= 1'b0;
+        end
+        else if (master_clear) begin
             terminal_count <= 1'b0;
-        else if (state == S4)
+            terminal_count_internal <= 1'b0;
+        end
+        else if (state == S4) begin
             terminal_count <= 1'b0;
-        else if (next_word)
+            terminal_count_internal <= 1'b0;
+        end
+        else if (next_word) begin
             terminal_count <= underflow;
-        else
+            terminal_count_internal <= underflow;
+        end
+        else begin
             terminal_count <= 1'b0;
+            terminal_count_internal <= terminal_count_internal;
+        end
     end
 
     assign  end_of_process_n_out = ~terminal_count;
@@ -552,23 +564,30 @@ module KF8237_Timing_And_Control (
         else if (master_clear)
             end_of_process_internal <= 1'b0;
         else if (next_state == S4)
-            end_of_process_internal <= terminal_count | external_end_of_process;
+            end_of_process_internal <= terminal_count_internal | external_end_of_process;
         else
             end_of_process_internal <= 1'b0;
     end
 
     //
     // Status Register
     //
+    always_ff @(negedge clock, posedge reset) begin
+        if (reset)
+            prev_read_status_register <= 1'b0;
+        else
+            prev_read_status_register <= read_status_register;
+    end
+
     always_ff @(negedge clock, posedge reset) begin
         if (reset)
             terminal_count_state <= 0;
         else if (master_clear)
             terminal_count_state <= 0;
-        else if (read_status_register)
+        else if (prev_read_status_register & ~read_status_register)
             terminal_count_state <= 0;
         else if (end_of_process_internal)
-            terminal_count_state <= dma_acknowledge_internal;
+            terminal_count_state <= terminal_count_state | dma_acknowledge_internal;
         else
             terminal_count_state <= terminal_count_state;
     end