From: Joshua Wise <joshua@rebirth.joshuawise.com>
Date: Sun, 11 May 2008 12:17:12 +0000 (-0400)
Subject: Add a first cut at strataflash support
X-Git-Url: http://git.joshuawise.com/fpgaboy.git/commitdiff_plain/8e36c4ed64993143adcbf103a7d4e4bc1ec627a1

Add a first cut at strataflash support
---

diff --git a/CoreTop.ucf b/CoreTop.ucf
index 55b4652..5e37410 100644
--- a/CoreTop.ucf
+++ b/CoreTop.ucf
@@ -103,5 +103,8 @@ NET "cr_A<20>" LOC="K3" | SLEW="fast";
 NET "cr_A<21>" LOC="D1" | SLEW="fast";
 NET "cr_A<22>" LOC="K6" | SLEW="fast";
 
+NET "st_nCE" LOC="R5" | SLEW="fast";
+NET "st_nRST" LOC="T5" | SLEW="fast";
+
 NET "ps2c" LOC="R12" | CLOCK_DEDICATED_ROUTE = FALSE;
-NET "ps2d" LOC="P11";
\ No newline at end of file
+NET "ps2d" LOC="P11";
diff --git a/System.v b/System.v
index 02b424c..e0baebe 100644
--- a/System.v
+++ b/System.v
@@ -81,6 +81,7 @@ module CellularRAM(
 	inout [7:0] data,
 	input wr, rd,
 	output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK,
+	output wire st_nCE, st_nRST,
 	output wire [22:0] cr_A,
 	inout [15:0] cr_DQ);
 	
@@ -88,6 +89,7 @@ module CellularRAM(
 	parameter ADDR_PROGADDRM = 16'hFF61;
 	parameter ADDR_PROGADDRL = 16'hFF62;
 	parameter ADDR_PROGDATA = 16'hFF63;
+	parameter ADDR_PROGFLASH = 16'hFF65;
 	parameter ADDR_MBC = 16'hFF64;
 	
 	reg rdlatch = 0, wrlatch = 0;
@@ -102,25 +104,28 @@ module CellularRAM(
 						// low 7 bits are the MBC that we are emulating
 	
 	assign cr_nADV = 0;	/* Addresses are always valid! :D */
-	assign cr_nCE = 0;	/* The chip is enabled */
+	assign cr_nCE = ~(addrlatch != ADDR_PROGFLASH);	/* The chip is enabled */
 	assign cr_nLB = 0;	/* Lower byte is enabled */
 	assign cr_nUB = 0;	/* Upper byte is enabled */
 	assign cr_CRE = 0;	/* Data writes, not config */
 	assign cr_CLK = 0;	/* Clock? I think not! */
 	
-	wire decode = (addrlatch[15:14] == 2'b00) /* extrom */ || (addrlatch[15:13] == 3'b101) /* extram */ || (addrlatch == ADDR_PROGDATA);
+	assign st_nRST = 1;	/* Keep the strataflash out of reset. */
+	assign st_nCE = ~(addrlatch == ADDR_PROGFLASH);
+	
+	wire decode = (addrlatch[15:14] == 2'b00) /* extrom */ || (addrlatch[15:13] == 3'b101) /* extram */ || (addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH);
 	
 	reg [3:0] rambank = 0;
 	reg [8:0] rombank = 1;
 	
 	assign cr_nOE = decode ? ~rdlatch : 1;
-	assign cr_nWE = (decode && ((addrlatch == ADDR_PROGDATA) || (mbc_emul[6:0] == 0) || (addrlatch[15:13] == 3'b101))) ? ~wrlatch : 1;
+	assign cr_nWE = (decode && ((addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH) || (mbc_emul[6:0] == 0) || (addrlatch[15:13] == 3'b101))) ? ~wrlatch : 1;
 	
 	assign cr_DQ = (~cr_nOE) ? 16'bzzzzzzzzzzzzzzzz : {8'b0, datalatch};
 	assign cr_A = (addrlatch[15:14] == 2'b00) ? /* extrom, home bank */ {9'b0,addrlatch[13:0]} :
 			(addrlatch[15:14] == 2'b01) ? /* extrom, paged bank */ {rombank, addrlatch[13:0]} :
 			(addrlatch[15:13] == 3'b101) ? /* extram */ {1'b1, 5'b0, rambank, addrlatch[12:0]} :
-			(addrlatch == ADDR_PROGDATA) ? progaddr :
+			((addrlatch == ADDR_PROGDATA) || (addrlatch == ADDR_PROGFLASH)) ? progaddr :
 			23'b0;
 	
 	always @(posedge clk) begin
@@ -229,7 +234,7 @@ module CoreTop(
 	input serin,
 	output wire [3:0] digits,
 	output wire [7:0] seven,
-	output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK,
+	output wire cr_nADV, cr_nCE, cr_nOE, cr_nWE, cr_CRE, cr_nLB, cr_nUB, cr_CLK, st_nCE, st_nRST,
 	output wire [22:0] cr_A,
 	inout [15:0] cr_DQ,
 	input ps2c, ps2d,
@@ -314,7 +319,9 @@ module CoreTop(
 		.cr_nUB(cr_nUB),
 		.cr_CLK(cr_CLK),
 		.cr_A(cr_A),
-		.cr_DQ(cr_DQ));
+		.cr_DQ(cr_DQ),
+		.st_nCE(st_nCE),
+		.st_nRST(st_nRST));
 `endif
 	
 	wire lcdhs, lcdvs, lcdclk;