[PLUS TOO] Optional 2.5x CPU Turbo

mist-devel · Nov 19, 2015 · 151479c · 151479c
1 parent 74d6acf
commit 151479c
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Showing 3 changed files with 15 additions and 8 deletions.
diff --git a/cores/plus_too/addrController_top.v b/cores/plus_too/addrController_top.v
@@ -3,6 +3,7 @@ module addrController_top(
 	input clk8,						// 8.125 MHz CPU clock
 
 	// system config:
+	input turbo,               // 0 = normal, 1 = faster
 	input configROMSize,			// 0 = 64K ROM, 1 = 128K ROM
 	input [1:0] configRAMSize,	// 0 = 128K, 1 = 512K, 2 = 1MB, 3 = 4MB RAM
 
@@ -117,9 +118,11 @@ module addrController_top(
 	// video controls memory bus during the first clock of the four-clock cycle
 	assign videoBusControl = (busCycle == 2'b00);
 	// cpu controls memory bus during the third clock of the four-clock cycle
-	assign cpuBusControl = (busCycle == 2'b10) && (subCycle != 2'd2);
-	//
-	wire extraBusControl = (busCycle == 2'b01);
+	assign cpuBusControl = turbo?cpuBusControl_fast:cpuBusControl_normal;
+	wire cpuBusControl_normal = (busCycle == 2'b01) && (subCycle != 2'd2);
+	wire cpuBusControl_fast = (busCycle == 2'b01) || (busCycle == 2'b11);
+
+	wire extraBusControl = (busCycle == 2'b10);
 
 	// interconnects
 	wire selectRAM, selectROM;

diff --git a/cores/plus_too/plusToo_top.v b/cores/plus_too/plusToo_top.v
@@ -107,7 +107,7 @@ always @(negedge dio_download or posedge diskEject[1]) begin
 		dsk_ext_ds <= 1'b0;
 		dsk_ext_ss <= 1'b0;
 	end else if(dio_index == 2) begin
-		dsk_ext_ds <= (dio_addr == 409599);   // double sides disk, addr counts words, not bytes
+		dsk_ext_ds <= (dio_addr == 409599);   // double sided disk, addr counts words, not bytes
 		dsk_ext_ss <= (dio_addr == 204799);   // single sided disk
 	end
 end
@@ -225,13 +225,15 @@ wire keyData;
         "F2,DSK;",
 		  "S3,IMG;",
 		  "O4,Memory,1MB,4MB;",
-        "T5,Reset"
+		  "O5,Speed,Normal,Turbo;",
+        "T6,Reset"
 	};
 
 	wire status_mem = status[4];
-	wire status_reset = status[5];
+	wire status_turbo = status[5];
+	wire status_reset = status[6];
 
-	parameter CONF_STR_LEN = 10+7+7+7+18+8;
+	parameter CONF_STR_LEN = 10+7+7+7+18+22+8;
 
 	// the status register is controlled by the on screen display (OSD)
 	wire [7:0] status;
@@ -307,6 +309,7 @@ wire keyData;
 		._cpuUDS(_cpuUDS),
 		._cpuLDS(_cpuLDS),
 		._cpuRW(_cpuRW), 
+		.turbo (status_turbo),
 		.configROMSize(configROMSize), 
 		.configRAMSize(configRAMSize), 
 		.memoryAddr(memoryAddr),			
@@ -348,7 +351,7 @@ wire keyData;
 	always @(posedge clk8) begin
 		last_mem_config <= status_mem;
 
-		// various source can reset the mac
+		// various sources can reset the mac
 		if(!pll_locked || status[0] || status_reset || buttons[1] || 
 			rom_download || (last_mem_config != status_mem)) 
 			rst_cnt <= 16'd65535;

diff --git a/cores/plus_too/readme.md b/cores/plus_too/readme.md
@@ -31,5 +31,6 @@ Functional changes:
 - fix mouse counter wrapping
 - Basic sound support
 - SCSI interface + SCSI hdd support
+- CPU Turbo mode (ca factor 2.5)
 
 Binaries are available at the [binaries repository](https://github.com/mist-devel/mist-binaries/tree/master/cores/plus_too).