├── README.md ├── output_files └── SMSCart.cdf ├── .gitignore ├── SMSCart.qpf ├── SMSMapper_tb.vhd ├── SMSCart.vhd ├── SMSCart.qsf ├── src └── SMSMapper.vhd └── LICENSE /README.md: -------------------------------------------------------------------------------- 1 | The SimpleMapper directory contains the VHDL for a bare bones mapper which attempts to replicate a Sega Mapper - no fancy features added. 2 | -------------------------------------------------------------------------------- /output_files/SMSCart.cdf: -------------------------------------------------------------------------------- 1 | /* Quartus II 64-Bit Version 13.0.1 Build 232 06/12/2013 Service Pack 1 SJ Web Edition */ 2 | JedecChain; 3 | FileRevision(JESD32A); 4 | DefaultMfr(6E); 5 | 6 | P ActionCode(Cfg) 7 | Device PartName(EPM3064AT100) Path("/home/rene/Git/Quartus/SMSMapper/output_files/") File("SMSCart.pof") MfrSpec(OpMask(3)); 8 | 9 | ChainEnd; 10 | 11 | AlteraBegin; 12 | ChainType(JTAG); 13 | AlteraEnd; 14 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # ignore Quartus II generated files 2 | *sopc_* 3 | *.jdi 4 | *.ptf.* 5 | *.sof 6 | *.pof 7 | *.qws 8 | *.smsg 9 | *_inst.vhd 10 | *_generation_script* 11 | *.done 12 | *.txt 13 | *.qarlog 14 | *.rpt 15 | *.summary 16 | *.qws 17 | *.cmp 18 | *.eqn 19 | *.html 20 | *.jpg 21 | *.bak 22 | *.qar 23 | *.sopc_builder 24 | *example* 25 | *~ 26 | *.sdc 27 | *.tcl 28 | *.pin 29 | *.mif 30 | *.hex 31 | 32 | # ignore Quartus II generated folders 33 | db/ 34 | incremental_db/ 35 | simulation/ 36 | timing/ 37 | testbench/ 38 | *_sim/ 39 | -------------------------------------------------------------------------------- /SMSCart.qpf: -------------------------------------------------------------------------------- 1 | # -------------------------------------------------------------------------- # 2 | # 3 | # Copyright (C) 1991-2013 Altera Corporation 4 | # Your use of Altera Corporation's design tools, logic functions 5 | # and other software and tools, and its AMPP partner logic 6 | # functions, and any output files from any of the foregoing 7 | # (including device programming or simulation files), and any 8 | # associated documentation or information are expressly subject 9 | # to the terms and conditions of the Altera Program License 10 | # Subscription Agreement, Altera MegaCore Function License 11 | # Agreement, or other applicable license agreement, including, 12 | # without limitation, that your use is for the sole purpose of 13 | # programming logic devices manufactured by Altera and sold by 14 | # Altera or its authorized distributors. Please refer to the 15 | # applicable agreement for further details. 16 | # 17 | # -------------------------------------------------------------------------- # 18 | # 19 | # Quartus II 64-Bit 20 | # Version 13.0.1 Build 232 06/12/2013 Service Pack 1 SJ Web Edition 21 | # Date created = 18:27:04 March 19, 2014 22 | # 23 | # -------------------------------------------------------------------------- # 24 | 25 | QUARTUS_VERSION = "13.0" 26 | DATE = "18:27:04 March 19, 2014" 27 | 28 | # Revisions 29 | 30 | PROJECT_REVISION = "SMSCart" 31 | -------------------------------------------------------------------------------- /SMSMapper_tb.vhd: -------------------------------------------------------------------------------- 1 | library std; 2 | use std.env.all; 3 | library IEEE; 4 | use IEEE.STD_LOGIC_1164.ALL; 5 | 6 | entity SMSMapper_tb is 7 | end SMSMapper_tb; 8 | 9 | architecture rtl of SMSMapper_tb is 10 | --input from sms 11 | signal ADDR : std_logic_vector(15 downto 0); 12 | signal DATA : std_logic_vector(7 downto 0); 13 | signal nRST : std_logic; 14 | signal nWR : std_logic; 15 | signal nCE : std_logic; 16 | 17 | --output to ROM 18 | signal nROMWE : std_logic; 19 | signal nROMCE : std_logic; 20 | signal ROMADDR1914 : std_logic_vector(5 downto 0); 21 | 22 | --output to serial EEPROM 23 | signal EE_CS : std_logic; 24 | signal EE_SO : std_logic; 25 | signal EE_SI : std_logic; 26 | signal EE_SCK : std_logic; 27 | 28 | --output to SRAM 29 | signal nSRAMCE : std_logic; 30 | signal nSRAMWE : std_logic; 31 | signal SRAMADDR14 : std_logic; 32 | begin 33 | 34 | SMSMapper_u0: entity work.SMSMapper 35 | port map( 36 | ADDR_p => ADDR, 37 | DATA_p => DATA, 38 | nRST_p => nRST, 39 | nWR_p => nWR, 40 | nCE_p => nCE, 41 | nROMWE_p => nROMWE, 42 | nROMCE_p => nROMCE, 43 | ROMADDR1914_p => ROMADDR1914, 44 | EE_CS_p => EE_CS, 45 | EE_SO_p => EE_SO, 46 | EE_SI_p => EE_SI, 47 | EE_SCK_p => EE_SCK, 48 | nSRAMCE_p => nSRAMCE, 49 | nSRAMWE_p => nSRAMWE, 50 | SRAMADDR14_p => SRAMADDR14 51 | ); 52 | 53 | sim: process 54 | begin 55 | nRST <= '0'; 56 | DATA <= ( others => 'Z'); 57 | nROMWE <= 'H'; 58 | nROMCE <= 'H'; 59 | ROMADDR1914 <= (others => 'H'); 60 | ADDR <= ( others => '1'); 61 | nCE <= '1'; 62 | nWR <= '1'; 63 | wait for 10 ns; 64 | 65 | nRST <= '1'; 66 | DATA <= x"04"; 67 | ADDR <= x"FFFD"; 68 | wait for 5 ns; 69 | 70 | nCE <= '0'; 71 | nWR <= '0'; 72 | wait for 15 ns; 73 | 74 | nCE <= '1'; 75 | nWR <= '1'; 76 | wait for 5 ns; 77 | 78 | ADDR <= x"2000"; 79 | wait for 5 ns; 80 | 81 | nCE <= '0'; 82 | wait for 15 ns; 83 | 84 | nCE <= '1'; 85 | wait for 5 ns; 86 | 87 | stop(0); 88 | end process; 89 | 90 | end architecture; -------------------------------------------------------------------------------- /SMSCart.vhd: -------------------------------------------------------------------------------- 1 | --************************************************************* 2 | -- db Mapper 3 | -- Copyright 2015 Rene Richard 4 | -- DEVICE : EPM3064ATC100-10 5 | --************************************************************* 6 | -- 7 | -- Description: 8 | -- This is a VHDL implementation of an SMS Sega Mapper 9 | -- it is intended to be used on the db Electronics SMS Homebrew Carts 10 | -- Supported Flash Memory Configurations: 11 | -- 2Mbit (1x 2Mbit) 12 | -- 4Mbit (1x 4Mbit) 13 | -- 8Mbit (1x 4Mbit) 14 | -- Support RAM Configurations 15 | -- 32KB 16 | -- 17 | -- for a complete description of SMS Mappers, go to http://www.smspower.org/Development/Mappers 18 | --************************************************************* 19 | -- 20 | -- RAM and Misc. Register 21 | -- $FFFC 22 | -- bit 7: ROM Write Enable 23 | -- when '1' writes to ROM (i.e. Flash) are enabled 24 | -- when '0' writes to mapper registers are enabled 25 | -- bit 3: RAM Enable 26 | -- when '1' RAM will be mapped into slot 2, overriding any ROM banking via $ffff 27 | -- when '0' ROM banking is effective 28 | -- bit 2: RAM Bank Select 29 | -- when '1' maps the upper 16KB of RAM into slot 2 30 | -- when '0' maps the lower 16KB of RAM into slot 2 31 | --************************************************************* 32 | 33 | library IEEE; 34 | use IEEE.STD_LOGIC_1164.ALL; 35 | 36 | entity SMSCart is 37 | 38 | port ( 39 | --input from sms 40 | ADDR_p : in std_logic_vector(15 downto 0); 41 | DATA_p : in std_logic_vector(7 downto 0); 42 | nRST_p : in std_logic; 43 | nWR_p : in std_logic; 44 | nCE_p : in std_logic; 45 | 46 | --output to ROM 47 | nROMWE_p : out std_logic; 48 | nROMCE_p : out std_logic; 49 | ROMADDR1914_p : out std_logic_vector(5 downto 0); 50 | 51 | --output to serial EEPROM 52 | EE_CS_p : out std_logic; 53 | EE_SO_p : out std_logic; 54 | EE_SI_p : out std_logic; 55 | EE_SCK_p : out std_logic; 56 | 57 | --output to SRAM 58 | nSRAMCE_p : out std_logic; 59 | nSRAMWE_p : out std_logic; 60 | SRAMADDR14_p : out std_logic 61 | ); 62 | end entity; 63 | 64 | architecture SMSCart_a of SMSCart is 65 | 66 | begin 67 | 68 | SMSMapper_inst: entity work.SMSMapper 69 | generic map( 70 | SLOT0ENABLE => true, 71 | SLOT1ENABLE => true 72 | ) 73 | port map( 74 | ADDR_p => ADDR_p, 75 | DATA_p => DATA_p, 76 | nRST_p => nRST_p, 77 | nWR_p => nWR_p, 78 | nCE_p => nCE_p, 79 | nROMWE_p => nROMWE_p, 80 | nROMCE_p => nROMCE_p, 81 | ROMADDR1914_p => ROMADDR1914_p, 82 | EE_CS_p => EE_CS_p, 83 | EE_SO_p => EE_SO_p, 84 | EE_SI_p => EE_SI_p, 85 | EE_SCK_p => EE_SCK_p, 86 | nSRAMCE_p => nSRAMCE_p, 87 | nSRAMWE_p => nSRAMWE_p, 88 | SRAMADDR14_p => SRAMADDR14_p 89 | ); 90 | 91 | end SMSCart_a; -------------------------------------------------------------------------------- /SMSCart.qsf: -------------------------------------------------------------------------------- 1 | # -------------------------------------------------------------------------- # 2 | # 3 | # Copyright (C) 1991-2013 Altera Corporation 4 | # Your use of Altera Corporation's design tools, logic functions 5 | # and other software and tools, and its AMPP partner logic 6 | # functions, and any output files from any of the foregoing 7 | # (including device programming or simulation files), and any 8 | # associated documentation or information are expressly subject 9 | # to the terms and conditions of the Altera Program License 10 | # Subscription Agreement, Altera MegaCore Function License 11 | # Agreement, or other applicable license agreement, including, 12 | # without limitation, that your use is for the sole purpose of 13 | # programming logic devices manufactured by Altera and sold by 14 | # Altera or its authorized distributors. Please refer to the 15 | # applicable agreement for further details. 16 | # 17 | # -------------------------------------------------------------------------- # 18 | # 19 | # Quartus II 64-Bit 20 | # Version 13.0.1 Build 232 06/12/2013 Service Pack 1 SJ Web Edition 21 | # Date created = 18:27:04 March 19, 2014 22 | # 23 | # -------------------------------------------------------------------------- # 24 | # 25 | # Notes: 26 | # 27 | # 1) The default values for assignments are stored in the file: 28 | # SMSCart_assignment_defaults.qdf 29 | # If this file doesn't exist, see file: 30 | # assignment_defaults.qdf 31 | # 32 | # 2) Altera recommends that you do not modify this file. This 33 | # file is updated automatically by the Quartus II software 34 | # and any changes you make may be lost or overwritten. 35 | # 36 | # -------------------------------------------------------------------------- # 37 | 38 | 39 | set_global_assignment -name FAMILY MAX3000A 40 | set_global_assignment -name DEVICE "EPM3064ATC100-10" 41 | set_global_assignment -name TOP_LEVEL_ENTITY SMSCart 42 | set_global_assignment -name ORIGINAL_QUARTUS_VERSION "13.0 SP1" 43 | set_global_assignment -name PROJECT_CREATION_TIME_DATE "18:27:04 MARCH 19, 2014" 44 | set_global_assignment -name LAST_QUARTUS_VERSION "13.0 SP1" 45 | set_global_assignment -name PROJECT_OUTPUT_DIRECTORY output_files 46 | set_global_assignment -name DEVICE_FILTER_PIN_COUNT 100 47 | set_global_assignment -name ERROR_CHECK_FREQUENCY_DIVISOR "-1" 48 | set_global_assignment -name SIMULATION_MODE FUNCTIONAL 49 | set_global_assignment -name EDA_SIMULATION_TOOL "ModelSim-Altera (Verilog)" 50 | set_global_assignment -name EDA_OUTPUT_DATA_FORMAT "VERILOG HDL" -section_id eda_simulation 51 | set_global_assignment -name EDA_GENERATE_FUNCTIONAL_NETLIST ON -section_id eda_simulation 52 | set_global_assignment -name OPTIMIZE_HOLD_TIMING OFF 53 | set_global_assignment -name OPTIMIZE_MULTI_CORNER_TIMING OFF 54 | set_global_assignment -name FITTER_EFFORT "STANDARD FIT" 55 | set_global_assignment -name EDA_TIME_SCALE "1 ns" -section_id eda_simulation 56 | set_global_assignment -name MAX7000_DEVICE_IO_STANDARD "3.3-V LVTTL" 57 | set_location_assignment PIN_44 -to ADDR_p[15] 58 | set_location_assignment PIN_45 -to ADDR_p[14] 59 | set_location_assignment PIN_76 -to ADDR_p[13] 60 | set_location_assignment PIN_8 -to ADDR_p[12] 61 | set_location_assignment PIN_60 -to ADDR_p[11] 62 | set_location_assignment PIN_80 -to ADDR_p[10] 63 | set_location_assignment PIN_58 -to ADDR_p[9] 64 | set_location_assignment PIN_48 -to ADDR_p[8] 65 | set_location_assignment PIN_9 -to ADDR_p[7] 66 | set_location_assignment PIN_10 -to ADDR_p[6] 67 | set_location_assignment PIN_12 -to ADDR_p[5] 68 | set_location_assignment PIN_13 -to ADDR_p[4] 69 | set_location_assignment PIN_14 -to ADDR_p[3] 70 | set_location_assignment PIN_100 -to ADDR_p[2] 71 | set_location_assignment PIN_99 -to ADDR_p[1] 72 | set_location_assignment PIN_98 -to ADDR_p[0] 73 | set_location_assignment PIN_83 -to DATA_p[7] 74 | set_location_assignment PIN_84 -to DATA_p[6] 75 | set_location_assignment PIN_85 -to DATA_p[5] 76 | set_location_assignment PIN_92 -to DATA_p[4] 77 | set_location_assignment PIN_93 -to DATA_p[3] 78 | set_location_assignment PIN_94 -to DATA_p[2] 79 | set_location_assignment PIN_96 -to DATA_p[1] 80 | set_location_assignment PIN_97 -to DATA_p[0] 81 | set_location_assignment PIN_89 -to nRST_p 82 | set_location_assignment PIN_81 -to nSRAMCE_p 83 | set_location_assignment PIN_42 -to nWR_p 84 | set_location_assignment PIN_6 -to SRAMADDR14_p 85 | set_global_assignment -name USE_CONFIGURATION_DEVICE ON 86 | set_global_assignment -name RESERVE_ALL_UNUSED_PINS_NO_OUTPUT_GND "AS INPUT TRI-STATED" 87 | set_location_assignment PIN_56 -to ROMADDR1914_p[5] 88 | set_location_assignment PIN_54 -to ROMADDR1914_p[4] 89 | set_location_assignment PIN_67 -to ROMADDR1914_p[3] 90 | set_location_assignment PIN_64 -to ROMADDR1914_p[2] 91 | set_location_assignment PIN_63 -to ROMADDR1914_p[1] 92 | set_location_assignment PIN_61 -to ROMADDR1914_p[0] 93 | set_location_assignment PIN_41 -to nCE_p 94 | set_location_assignment PIN_47 -to nROMCE_p 95 | set_location_assignment PIN_57 -to nROMWE_p 96 | set_location_assignment PIN_68 -to EE_CS_p 97 | set_location_assignment PIN_71 -to EE_SCK_p 98 | set_location_assignment PIN_75 -to EE_SI_p 99 | set_location_assignment PIN_69 -to EE_SO_p 100 | set_location_assignment PIN_79 -to nSRAMWE_p 101 | set_location_assignment PIN_46 -to nOE_p 102 | set_global_assignment -name PARTITION_NETLIST_TYPE SOURCE -section_id Top 103 | set_global_assignment -name PARTITION_FITTER_PRESERVATION_LEVEL PLACEMENT_AND_ROUTING -section_id Top 104 | set_global_assignment -name PARTITION_COLOR 16764057 -section_id Top 105 | set_instance_assignment -name PARTITION_HIERARCHY root_partition -to | -section_id Top 106 | set_global_assignment -name INCREMENTAL_VECTOR_INPUT_SOURCE /home/rene/Git/Quartus/SMSMapper/sim/SMSCart.vwf 107 | set_global_assignment -name EDA_TEST_BENCH_ENABLE_STATUS TEST_BENCH_MODE -section_id eda_simulation 108 | set_global_assignment -name EDA_NATIVELINK_SIMULATION_TEST_BENCH SMSMapper_tb -section_id eda_simulation 109 | set_global_assignment -name EDA_TEST_BENCH_NAME SMSMapper_tb -section_id eda_simulation 110 | set_global_assignment -name EDA_DESIGN_INSTANCE_NAME SMSMapper_tb -section_id SMSMapper_tb 111 | set_global_assignment -name EDA_TEST_BENCH_MODULE_NAME SMSMapper_tb -section_id SMSMapper_tb 112 | set_global_assignment -name EDA_TEST_BENCH_FILE SMSMapper_tb.vhd -section_id SMSMapper_tb 113 | set_global_assignment -name VHDL_FILE src/SMSMapper.vhd 114 | set_global_assignment -name VHDL_FILE SMSCart.vhd -------------------------------------------------------------------------------- /src/SMSMapper.vhd: -------------------------------------------------------------------------------- 1 | --************************************************************* 2 | -- db Mapper 3 | -- Copyright 2015 Rene Richard 4 | -- DEVICE : EPM3064ATC100-10 5 | --************************************************************* 6 | -- 7 | -- Description: 8 | -- This is a VHDL implementation of an SMS Sega Mapper 9 | -- it is intended to be used on the db Electronics SMS Homebrew Carts 10 | -- Supported Flash Memory Configurations: 11 | -- 2Mbit (1x 2Mbit) 12 | -- 4Mbit (1x 4Mbit) 13 | -- 8Mbit (1x 4Mbit) 14 | -- Support RAM Configurations 15 | -- 32KB 16 | -- 17 | -- for a complete description of SMS Mappers, go to http://www.smspower.org/Development/Mappers 18 | --************************************************************* 19 | -- 20 | -- RAM and Misc. Register 21 | -- $FFFC 22 | -- bit 7: ROM Write Enable 23 | -- when '1' writes to ROM (i.e. Flash) are enabled 24 | -- when '0' writes to mapper registers are enabled 25 | -- bit 3: RAM Enable 26 | -- when '1' RAM will be mapped into slot 2, overriding any ROM banking via $ffff 27 | -- when '0' ROM banking is effective 28 | -- bit 2: RAM Bank Select 29 | -- when '1' maps the upper 16KB of RAM into slot 2 30 | -- when '0' maps the lower 16KB of RAM into slot 2 31 | --************************************************************* 32 | 33 | library IEEE; 34 | use IEEE.STD_LOGIC_1164.ALL; 35 | 36 | entity SMSMapper is 37 | 38 | generic( 39 | SLOT0ENABLE : boolean := true; 40 | SLOT1ENABLE : boolean := true 41 | ); 42 | 43 | port ( 44 | --input from sms 45 | ADDR_p : in std_logic_vector(15 downto 0); 46 | DATA_p : in std_logic_vector(7 downto 0); 47 | nRST_p : in std_logic; 48 | nWR_p : in std_logic; 49 | nCE_p : in std_logic; 50 | 51 | --output to ROM 52 | nROMWE_p : out std_logic; 53 | nROMCE_p : out std_logic; 54 | ROMADDR1914_p : out std_logic_vector(5 downto 0); 55 | 56 | --output to serial EEPROM 57 | EE_CS_p : out std_logic; 58 | EE_SO_p : out std_logic; 59 | EE_SI_p : out std_logic; 60 | EE_SCK_p : out std_logic; 61 | 62 | --output to SRAM 63 | nSRAMCE_p : out std_logic; 64 | nSRAMWE_p : out std_logic; 65 | SRAMADDR14_p : out std_logic 66 | ); 67 | end entity; 68 | 69 | architecture SMSMapper_a of SMSMapper is 70 | 71 | --internal data and address signals for easy write back if ever needed 72 | signal datain_s : std_logic_vector(7 downto 0); 73 | signal addr_s : std_logic_vector(15 downto 0); 74 | 75 | --Mapper slot registers, fitter will optimize any unused bits 76 | signal romSlot1_s : std_logic_vector(5 downto 0); 77 | signal romSlot2_s : std_logic_vector(5 downto 0); 78 | signal mapAddr_s : std_logic_vector(5 downto 0); 79 | 80 | --internal rom signals 81 | signal romWrEn_s : std_logic; 82 | signal nRomCE_s : std_logic; 83 | signal nRomWE_s : std_logic; 84 | 85 | --RAM mapping signals 86 | signal ramEn_s : std_logic; 87 | signal ramBank_s : std_logic; 88 | 89 | begin 90 | 91 | --internal data and address signals 92 | addr_s <= ADDR_p; 93 | datain_s <= DATA_p; 94 | 95 | --output mapping to ROM and RAM 96 | SRAMADDR14_p <= ramBank_s; 97 | 98 | --high order address bits and WE and CE must be open-drain to meet 5V requirements 99 | -- 1K pull-up on each of these lines 100 | ROMADDR1914_p(0) <= '0' when mapAddr_s(0) = '0' else 'Z'; 101 | ROMADDR1914_p(1) <= '0' when mapAddr_s(1) = '0' else 'Z'; 102 | ROMADDR1914_p(2) <= '0' when mapAddr_s(2) = '0' else 'Z'; 103 | ROMADDR1914_p(3) <= '0' when mapAddr_s(3) = '0' else 'Z'; 104 | ROMADDR1914_p(4) <= '0' when mapAddr_s(4) = '0' else 'Z'; 105 | ROMADDR1914_p(5) <= '0' when mapAddr_s(5) = '0' else 'Z'; 106 | 107 | --ROM Write Gating with bit7 of $FFFC 108 | nRomWE_s <= nWR_p when romWrEn_s = '1' else '1'; 109 | nROMWE_p <= '0' when nRomWE_s = '0' else 'Z'; 110 | nROMCE_p <= '0' when nRomCE_s = '0' else 'Z'; 111 | 112 | --default values for now, todo later 113 | EE_CS_p <= '1'; 114 | EE_SO_p <= '1'; 115 | EE_SI_p <= '1'; 116 | EE_SCK_p <= '1'; 117 | 118 | --RAM mapping and miscellaneous functions register 119 | ram0: process( nRST_p, nWR_p, nCE_p, addr_s ) 120 | begin 121 | if nRST_p = '0' then 122 | romWrEn_s <= '0'; 123 | ramEn_s <= '0'; 124 | ramBank_s <= '0'; 125 | --nWR rises before address and mreq on Z80 126 | elsif falling_edge(nWR_p) then 127 | if addr_s = x"FFFC" and nCE_p = '0' then 128 | romWrEn_s <= datain_s(7); 129 | ramEn_s <= datain_s(3); 130 | ramBank_s <= datain_s(2); 131 | end if; 132 | end if; 133 | end process; 134 | 135 | --mapper registers 136 | mappers: process( nRST_p, nWR_p, nCE_p, addr_s) 137 | begin 138 | if nRST_p = '0' then 139 | romSlot1_s <= "000001"; 140 | romSlot2_s <= "000010"; 141 | --nWR rises before address and mreq on Z80 142 | elsif falling_edge(nWR_p) then 143 | if nCE_p = '0' then 144 | case addr_s is 145 | when x"FFFE" => 146 | romSlot1_s <= datain_s(5 downto 0); 147 | when x"FFFF" => 148 | romSlot2_s <= datain_s(5 downto 0); 149 | when others => 150 | null; 151 | end case; 152 | end if; 153 | end if; 154 | end process; 155 | 156 | --banking select 157 | --only looks at address, this way the address setup and hold times can be respected 158 | banking: process( addr_s ) 159 | begin 160 | mapAddr_s <= (others=>'0'); 161 | case addr_s(15 downto 14) is 162 | when "01" => 163 | mapAddr_s <= romSlot1_s(5 downto 0); 164 | when "10" => 165 | mapAddr_s <= romSlot2_s(5 downto 0); 166 | when others => 167 | mapAddr_s <= (others=>'0'); 168 | end case; 169 | end process; 170 | 171 | --drive chip select lines 172 | chipSelect: process( addr_s, ramEn_s, nCE_p ) 173 | begin 174 | nSRAMWE_p <= '1'; 175 | nSRAMCE_p <= '1'; 176 | nRomCE_s <= '1'; 177 | case addr_s(15 downto 14) is 178 | --slot 0 179 | when "00" => 180 | nRomCE_s <= nCE_p; 181 | --slot 1 182 | when "01" => 183 | nRomCE_s <= nCE_p; 184 | --slot 2 185 | when "10" => 186 | --RAM mapping has priority in Slot 2 187 | if ramEn_s = '1' then 188 | nSRAMCE_p <= nCE_p; 189 | nSRAMWE_p <= nWR_p; 190 | else 191 | --select upper or lower ROM based on A19 192 | nRomCE_s <= nCE_p; 193 | end if; 194 | when others => 195 | --don't drive anything in slot 4 196 | nSRAMWE_p <= '1'; 197 | nSRAMCE_p <= '1'; 198 | nRomCE_s <= '1'; 199 | end case; 200 | end process; 201 | 202 | end SMSMapper_a; -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. 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You may copy and distribute verbatim copies of the Program's 80 | source code as you receive it, in any medium, provided that you 81 | conspicuously and appropriately publish on each copy an appropriate 82 | copyright notice and disclaimer of warranty; keep intact all the 83 | notices that refer to this License and to the absence of any warranty; 84 | and give any other recipients of the Program a copy of this License 85 | along with the Program. 86 | 87 | You may charge a fee for the physical act of transferring a copy, and 88 | you may at your option offer warranty protection in exchange for a fee. 89 | 90 | 2. You may modify your copy or copies of the Program or any portion 91 | of it, thus forming a work based on the Program, and copy and 92 | distribute such modifications or work under the terms of Section 1 93 | above, provided that you also meet all of these conditions: 94 | 95 | a) You must cause the modified files to carry prominent notices 96 | stating that you changed the files and the date of any change. 97 | 98 | b) You must cause any work that you distribute or publish, that in 99 | whole or in part contains or is derived from the Program or any 100 | part thereof, to be licensed as a whole at no charge to all third 101 | parties under the terms of this License. 102 | 103 | c) If the modified program normally reads commands interactively 104 | when run, you must cause it, when started running for such 105 | interactive use in the most ordinary way, to print or display an 106 | announcement including an appropriate copyright notice and a 107 | notice that there is no warranty (or else, saying that you provide 108 | a warranty) and that users may redistribute the program under 109 | these conditions, and telling the user how to view a copy of this 110 | License. (Exception: if the Program itself is interactive but 111 | does not normally print such an announcement, your work based on 112 | the Program is not required to print an announcement.) 113 | 114 | These requirements apply to the modified work as a whole. If 115 | identifiable sections of that work are not derived from the Program, 116 | and can be reasonably considered independent and separate works in 117 | themselves, then this License, and its terms, do not apply to those 118 | sections when you distribute them as separate works. But when you 119 | distribute the same sections as part of a whole which is a work based 120 | on the Program, the distribution of the whole must be on the terms of 121 | this License, whose permissions for other licensees extend to the 122 | entire whole, and thus to each and every part regardless of who wrote it. 123 | 124 | Thus, it is not the intent of this section to claim rights or contest 125 | your rights to work written entirely by you; rather, the intent is to 126 | exercise the right to control the distribution of derivative or 127 | collective works based on the Program. 128 | 129 | In addition, mere aggregation of another work not based on the Program 130 | with the Program (or with a work based on the Program) on a volume of 131 | a storage or distribution medium does not bring the other work under 132 | the scope of this License. 133 | 134 | 3. You may copy and distribute the Program (or a work based on it, 135 | under Section 2) in object code or executable form under the terms of 136 | Sections 1 and 2 above provided that you also do one of the following: 137 | 138 | a) Accompany it with the complete corresponding machine-readable 139 | source code, which must be distributed under the terms of Sections 140 | 1 and 2 above on a medium customarily used for software interchange; or, 141 | 142 | b) Accompany it with a written offer, valid for at least three 143 | years, to give any third party, for a charge no more than your 144 | cost of physically performing source distribution, a complete 145 | machine-readable copy of the corresponding source code, to be 146 | distributed under the terms of Sections 1 and 2 above on a medium 147 | customarily used for software interchange; or, 148 | 149 | c) Accompany it with the information you received as to the offer 150 | to distribute corresponding source code. (This alternative is 151 | allowed only for noncommercial distribution and only if you 152 | received the program in object code or executable form with such 153 | an offer, in accord with Subsection b above.) 154 | 155 | The source code for a work means the preferred form of the work for 156 | making modifications to it. For an executable work, complete source 157 | code means all the source code for all modules it contains, plus any 158 | associated interface definition files, plus the scripts used to 159 | control compilation and installation of the executable. However, as a 160 | special exception, the source code distributed need not include 161 | anything that is normally distributed (in either source or binary 162 | form) with the major components (compiler, kernel, and so on) of the 163 | operating system on which the executable runs, unless that component 164 | itself accompanies the executable. 165 | 166 | If distribution of executable or object code is made by offering 167 | access to copy from a designated place, then offering equivalent 168 | access to copy the source code from the same place counts as 169 | distribution of the source code, even though third parties are not 170 | compelled to copy the source along with the object code. 171 | 172 | 4. You may not copy, modify, sublicense, or distribute the Program 173 | except as expressly provided under this License. Any attempt 174 | otherwise to copy, modify, sublicense or distribute the Program is 175 | void, and will automatically terminate your rights under this License. 176 | However, parties who have received copies, or rights, from you under 177 | this License will not have their licenses terminated so long as such 178 | parties remain in full compliance. 179 | 180 | 5. You are not required to accept this License, since you have not 181 | signed it. However, nothing else grants you permission to modify or 182 | distribute the Program or its derivative works. These actions are 183 | prohibited by law if you do not accept this License. Therefore, by 184 | modifying or distributing the Program (or any work based on the 185 | Program), you indicate your acceptance of this License to do so, and 186 | all its terms and conditions for copying, distributing or modifying 187 | the Program or works based on it. 188 | 189 | 6. Each time you redistribute the Program (or any work based on the 190 | Program), the recipient automatically receives a license from the 191 | original licensor to copy, distribute or modify the Program subject to 192 | these terms and conditions. You may not impose any further 193 | restrictions on the recipients' exercise of the rights granted herein. 194 | You are not responsible for enforcing compliance by third parties to 195 | this License. 196 | 197 | 7. If, as a consequence of a court judgment or allegation of patent 198 | infringement or for any other reason (not limited to patent issues), 199 | conditions are imposed on you (whether by court order, agreement or 200 | otherwise) that contradict the conditions of this License, they do not 201 | excuse you from the conditions of this License. If you cannot 202 | distribute so as to satisfy simultaneously your obligations under this 203 | License and any other pertinent obligations, then as a consequence you 204 | may not distribute the Program at all. For example, if a patent 205 | license would not permit royalty-free redistribution of the Program by 206 | all those who receive copies directly or indirectly through you, then 207 | the only way you could satisfy both it and this License would be to 208 | refrain entirely from distribution of the Program. 209 | 210 | If any portion of this section is held invalid or unenforceable under 211 | any particular circumstance, the balance of the section is intended to 212 | apply and the section as a whole is intended to apply in other 213 | circumstances. 214 | 215 | It is not the purpose of this section to induce you to infringe any 216 | patents or other property right claims or to contest validity of any 217 | such claims; this section has the sole purpose of protecting the 218 | integrity of the free software distribution system, which is 219 | implemented by public license practices. Many people have made 220 | generous contributions to the wide range of software distributed 221 | through that system in reliance on consistent application of that 222 | system; it is up to the author/donor to decide if he or she is willing 223 | to distribute software through any other system and a licensee cannot 224 | impose that choice. 225 | 226 | This section is intended to make thoroughly clear what is believed to 227 | be a consequence of the rest of this License. 228 | 229 | 8. If the distribution and/or use of the Program is restricted in 230 | certain countries either by patents or by copyrighted interfaces, the 231 | original copyright holder who places the Program under this License 232 | may add an explicit geographical distribution limitation excluding 233 | those countries, so that distribution is permitted only in or among 234 | countries not thus excluded. In such case, this License incorporates 235 | the limitation as if written in the body of this License. 236 | 237 | 9. The Free Software Foundation may publish revised and/or new versions 238 | of the General Public License from time to time. Such new versions will 239 | be similar in spirit to the present version, but may differ in detail to 240 | address new problems or concerns. 241 | 242 | Each version is given a distinguishing version number. If the Program 243 | specifies a version number of this License which applies to it and "any 244 | later version", you have the option of following the terms and conditions 245 | either of that version or of any later version published by the Free 246 | Software Foundation. If the Program does not specify a version number of 247 | this License, you may choose any version ever published by the Free Software 248 | Foundation. 249 | 250 | 10. If you wish to incorporate parts of the Program into other free 251 | programs whose distribution conditions are different, write to the author 252 | to ask for permission. For software which is copyrighted by the Free 253 | Software Foundation, write to the Free Software Foundation; we sometimes 254 | make exceptions for this. Our decision will be guided by the two goals 255 | of preserving the free status of all derivatives of our free software and 256 | of promoting the sharing and reuse of software generally. 257 | 258 | NO WARRANTY 259 | 260 | 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 261 | FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 262 | OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 263 | PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 264 | OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 265 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 266 | TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 267 | PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 268 | REPAIR OR CORRECTION. 269 | 270 | 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 271 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 272 | REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 273 | INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 274 | OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 275 | TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 276 | YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 277 | PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 278 | POSSIBILITY OF SUCH DAMAGES. 279 | 280 | END OF TERMS AND CONDITIONS 281 | 282 | How to Apply These Terms to Your New Programs 283 | 284 | If you develop a new program, and you want it to be of the greatest 285 | possible use to the public, the best way to achieve this is to make it 286 | free software which everyone can redistribute and change under these terms. 287 | 288 | To do so, attach the following notices to the program. It is safest 289 | to attach them to the start of each source file to most effectively 290 | convey the exclusion of warranty; and each file should have at least 291 | the "copyright" line and a pointer to where the full notice is found. 292 | 293 | {description} 294 | Copyright (C) {year} {fullname} 295 | 296 | This program is free software; you can redistribute it and/or modify 297 | it under the terms of the GNU General Public License as published by 298 | the Free Software Foundation; either version 2 of the License, or 299 | (at your option) any later version. 300 | 301 | This program is distributed in the hope that it will be useful, 302 | but WITHOUT ANY WARRANTY; without even the implied warranty of 303 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 | GNU General Public License for more details. 305 | 306 | You should have received a copy of the GNU General Public License along 307 | with this program; if not, write to the Free Software Foundation, Inc., 308 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 | 310 | Also add information on how to contact you by electronic and paper mail. 311 | 312 | If the program is interactive, make it output a short notice like this 313 | when it starts in an interactive mode: 314 | 315 | Gnomovision version 69, Copyright (C) year name of author 316 | Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 | This is free software, and you are welcome to redistribute it 318 | under certain conditions; type `show c' for details. 319 | 320 | The hypothetical commands `show w' and `show c' should show the appropriate 321 | parts of the General Public License. Of course, the commands you use may 322 | be called something other than `show w' and `show c'; they could even be 323 | mouse-clicks or menu items--whatever suits your program. 324 | 325 | You should also get your employer (if you work as a programmer) or your 326 | school, if any, to sign a "copyright disclaimer" for the program, if 327 | necessary. Here is a sample; alter the names: 328 | 329 | Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 | `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 | 332 | {signature of Ty Coon}, 1 April 1989 333 | Ty Coon, President of Vice 334 | 335 | This General Public License does not permit incorporating your program into 336 | proprietary programs. If your program is a subroutine library, you may 337 | consider it more useful to permit linking proprietary applications with the 338 | library. If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. 340 | 341 | --------------------------------------------------------------------------------