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fix the rom module for proper bram generation

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This commit is contained in:
Raphael Jacquot 2019-03-03 13:03:12 +01:00
parent 391e5b6e93
commit 9cb1618acb
1 changed files with 13 additions and 9 deletions
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22
saturn_hp48gx_rom.v
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@ -20,14 +20,14 @@
`default_nettype none
`include "saturn_def_buscmd.v"
`ifdef SIM
`define ROMBITS 20
`else
`define ROMBITS 12
`endif
`include "saturn_def_buscmd.v"
module saturn_hp48gx_rom (
i_clk,
i_reset,
@ -59,7 +59,6 @@ reg [19:0] local_pc;
reg [19:0] local_dp;
initial begin
o_bus_nibble_out = 4'b0;
last_cmd = 4'b0;
addr_pos_ctr = 3'b0;
local_pc = 20'b0;
@ -67,7 +66,7 @@ initial begin
end
/*
* special cases for reading the rom
* reading the rom
*/
wire [0:0] do_pc_read = (last_cmd == `BUSCMD_PC_READ);
@ -75,13 +74,19 @@ wire [0:0] do_dp_read = (last_cmd == `BUSCMD_DP_READ);
wire [0:0] do_read = do_pc_read || do_dp_read;
wire [0:0] can_read = i_bus_clk_en && i_bus_is_data && do_read;
wire [`ROMBITS-1:0] access_pointer = do_pc_read?local_pc[`ROMBITS-1:0]:local_dp[`ROMBITS-1:0];
wire [19:0] access_pointer = do_pc_read?local_pc:local_dp;
wire [`ROMBITS-1:0] address = access_pointer[`ROMBITS-1:0];
always @(posedge i_clk) begin
if (can_read)
o_bus_nibble_out <= rom_data[access_pointer];
o_bus_nibble_out <= rom_data[address];
end
`ifdef SIM
wire [3:0] imm_nibble = rom_data[address];
`endif
/*
* general case
*/
@ -95,7 +100,6 @@ always @(posedge i_clk) begin
begin
// o_bus_nibble_out <= rom_data[local_pc[`ROMBITS-1:0]];
local_pc <= local_pc + 1;
end
`BUSCMD_DP_READ:
begin
@ -129,8 +133,8 @@ always @(posedge i_clk) begin
`ifdef SIM
$write("ROM-GX-R %0d: [%d] ", i_phase, i_cycle_ctr);
case (last_cmd)
`BUSCMD_PC_READ: $write("PC_READ <= rom[%5h]:%h", local_pc, rom_data[local_pc]);
`BUSCMD_DP_READ: $write("DP_READ <= rom[%5h]:%h", local_dp, rom_data[local_dp]);
`BUSCMD_PC_READ: $write("PC_READ <= rom[%5h]:%h", local_pc, imm_nibble);
`BUSCMD_DP_READ: $write("DP_READ <= rom[%5h]:%h", local_dp, imm_nibble);
`BUSCMD_LOAD_PC: $write("LOAD_PC - pc %5h, %h pos %0d", local_pc, i_bus_nibble_in, addr_pos_ctr);
`BUSCMD_LOAD_DP: $write("LOAD_PC - pc %5h, %h pos %0d", local_pc, i_bus_nibble_in, addr_pos_ctr);
default: $write("last_command %h nibble %h - UNHANDLED", last_cmd, i_bus_nibble_in);