| Line 61... |
Line 61... |
output wire SRAM_OE_N,
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output wire SRAM_OE_N,
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output wire SRAM_WE_N,
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output wire SRAM_WE_N,
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output wire SRAM_UB_N,
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output wire SRAM_UB_N,
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output wire SRAM_LB_N,
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output wire SRAM_LB_N,
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|
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//-------- My little imitation of a Kempston joystick -----------
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//-------- Atari joystick mapped as Kempston
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input wire [5:0] kempston,
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input wire [4:0] kempston, // Input with weak pull-up
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output wire kempston_gnd, // Helps mapping to DB9 cable
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output wire [4:0] LEDG, // Show the joystick state
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output wire [4:0] LEDG, // Show the joystick state
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|
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//-------- Misc and debug -------------------
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//-------- Misc and debug -------------------
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input wire SW0, // ROM selection
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input wire SW0, // ROM selection
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input wire SW1, // Enable/disable interrupts
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input wire SW1, // Enable/disable interrupts
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| Line 83... |
Line 84... |
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// Export selected pins to the extension connector
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// Export selected pins to the extension connector
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assign GPIO_1[15:0] = A[15:0];
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assign GPIO_1[15:0] = A[15:0];
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assign GPIO_1[23:16] = D[7:0];
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assign GPIO_1[23:16] = D[7:0];
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assign GPIO_1[31:24] = {nM1,nMREQ,nIORQ,nRD,nWR,nRFSH,nHALT,nBUSACK};
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assign GPIO_1[31:24] = {nM1,nMREQ,nIORQ,nRD,nWR,nRFSH,nHALT,nBUSACK};
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assign kempston_gnd = 0;
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|
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// Top 3 green LEDs show various states:
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// Top 3 green LEDs show various states:
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assign LEDGTOP[2] = 0; // Reserved for future use
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assign LEDGTOP[2] = 0; // Reserved for future use
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assign LEDGTOP[1] = beeper; // Show the beeper state
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assign LEDGTOP[1] = beeper; // Show the beeper state
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assign LEDGTOP[0] = pressed; // Show when a key is being pressed
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assign LEDGTOP[0] = pressed; // Show when a key is being pressed
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| Line 127... |
Line 129... |
// ---------------------------------- IO read ----------------------------------
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// ---------------------------------- IO read ----------------------------------
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3'b001: begin
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3'b001: begin
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// Normally data supplied by the ULA
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// Normally data supplied by the ULA
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D[7:0] = ula_data;
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D[7:0] = ula_data;
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|
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// Kempston joystick at the IO address of 0x1F: active bits are high: 000FUDLR
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// Kempston joystick at the IO address 0x1F; active bits are high:
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// The bits are scrambled since I just happen to solder them that way on a game
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// FIRE UP DOWN LEFT RIGHT
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// pad I've got (see my blog); you can remap it if you have another kind of joystick
|
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if (A[7:0]==8'h1F) begin
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if (A[7:0]==8'h1F) begin
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D[7:0] = { 3'b0, !kempston[3],!kempston[5],!kempston[4],!kempston[0],!kempston[2] };
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D[7:0] = { 3'b0, !kempston[4],!kempston[0],!kempston[1],!kempston[2],!kempston[3] };
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end
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end
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end
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end
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default:
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default:
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D[7:0] = {8{1'bz}};
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D[7:0] = {8{1'bz}};
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endcase
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endcase
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| Line 282... |
Line 283... |
);
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);
|
|
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// Lit green LEDs to show activity on a Kempston compatible joystick
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// Lit green LEDs to show activity on a Kempston compatible joystick
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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assign LEDG[0] = !kempston[5]; // UP
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assign LEDG[0] = !kempston[0]; // UP
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assign LEDG[1] = !kempston[4]; // DOWN
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assign LEDG[1] = !kempston[1]; // DOWN
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assign LEDG[2] = !kempston[0]; // LEFT
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assign LEDG[2] = !kempston[2]; // LEFT
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assign LEDG[3] = !kempston[2]; // RIGHT
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assign LEDG[3] = !kempston[3]; // RIGHT
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assign LEDG[4] = !kempston[3] | !kempston[1]; // BUTTON
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assign LEDG[4] = !kempston[4]; // FIRE
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|
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endmodule
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endmodule
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