I2C_BOOTLOADER: Several fixes and a 4.5x performance increase as well as the addition of 16bit reads from the I2C_driver

boot_code/i2c_bootloader.asm

@@ -19,74 +19,123 @@ outb #0x63
 mov al,#0x00
 outb #0x60
 
-;wait_send: inw #0x62
-;test al,#0x01
-;jnz wait_send
 
-mov ax,#0x1FFE
+wait_send: inb #0x62
-aa:
+test al,#0x01
-dec ax
+jnz wait_send
-jnz aa
 
 mov bx,#OK_loading_txt
 call print
 
 
-;############ READ 20% ##################
+;############ READ CODE ##################
 
-mov bx,#0xD000
+mov bx,#0xEFFF
 mov di,#0x0000
 rom_read_loop:
-mov al,#0x05 ; Read, 8bit, ignore ack
+mov al,#0x07 ; Read, 8bit, ignore ack
 outb #0x63
 
 mov al,#0x00
 outb #0x60
 
-mov ax,#0x1FFE
+push bx
-aa2:
+cmp di,#0x1800
-dec ax
+jz print_10
-jnz aa2
+cmp di,#0x3000
+jz print_20
+cmp di,#0x4800
+jz print_30
+cmp di,#0x6000
+jz print_40
+cmp di,#0x7800
+jz print_50
+cmp di,#0x9000
+jz print_60
+cmp di,#0xA800
+jz print_70
+cmp di,#0xC000
+jz print_80
+cmp di,#0xD800
+jz print_90
+back:
+pop bx
+
+wait_send2: inb #0x62
+test al,#0x01
+jnz wait_send2
 
 inw #0x60
-STOSB
+;MOV CL,AH
-
+;MOV AH,AL
-cmp di,#0x2999
+;MOV AL,CL
-jz print_20
+STOSW
-cmp di,#0x5333
-jz print_40
-cmp di,#0x7CCC
-jz print_60
-cmp di,#0xA666
-jz print_80
-
-back:dec bx
-jnz rom_read_loop
 
 
+dec bx
+jz rom_read_end
+dec bx
+jz rom_read_end
+jmp rom_read_loop
+
+rom_read_end:
 MOV AX,#0xC000
 JMP AX
 
+print_10:
+mov cx,#ten_prc_txt
+call print_prc
+jmp back
+
 print_20:
-mov bx,#twenty_prc_txt
+mov cx,#twenty_prc_txt
-call print
+call print_prc
+jmp back
+
+print_30:
+mov cx,#thirty_prc_txt
+call print_prc
 jmp back
 
 print_40:
-mov bx,#forty_prc_txt
+mov cx,#forty_prc_txt
-call print
+call print_prc
+jmp back
+
+print_50:
+mov cx,#fifty_prc_txt
+call print_prc
 jmp back
 
 print_60:
-mov bx,#sixty_prc_txt
+mov cx,#sixty_prc_txt
-call print
+call print_prc
+jmp back
+
+print_70:
+mov cx,#seventy_prc_txt
+call print_prc
 jmp back
 
 print_80:
-mov bx,#eighty_prc_txt
+mov cx,#eighty_prc_txt
-call print
+call print_prc
 jmp back
 
+print_90:
+mov cx,#ninty_prc_txt
+call print_prc
+jmp back
+
+print_prc:
+mov bx,#loading_rom_txt
+call print
+mov bx,cx
+call print
+ret
+
+;#########################################
+
 
 include LiteDram_init.asm
 
@@ -105,10 +154,16 @@ STACK: ; brainfuck_mandelbrot depends on stack being at the end
 
 load_i2c_txt: .ASCII 'Read I2C EEPROM:\0'
 OK_loading_txt: .ASCII 'OK\nLoading rom  0%\r\0'
-twenty_prc_txt:     .ASCII 'Loading rom 20%\r\0'
+loading_rom_txt:        .ASCII 'Loading rom \0'
-forty_prc_txt:      .ASCII 'Loading rom 40%\r\0'
+ten_prc_txt:        .ASCII '10%\r\0'
-sixty_prc_txt:      .ASCII 'Loading rom 60%\r\0'
+twenty_prc_txt:     .ASCII '20%\r\0'
-eighty_prc_txt:     .ASCII 'Loading rom 80%\r\0'
+thirty_prc_txt:     .ASCII '30%\r\0'
+forty_prc_txt:      .ASCII '40%\r\0'
+fifty_prc_txt:      .ASCII '50%\r\0'
+sixty_prc_txt:      .ASCII '60%\r\0'
+seventy_prc_txt:    .ASCII '70%\r\0'
+eighty_prc_txt:     .ASCII '80%\r\0'
+ninty_prc_txt:      .ASCII '90%\r\0'
 
 .ORG 0xFFF0
 MOV AX,#0xF800

system/peripherals/I2C_driver.v

@@ -38,7 +38,7 @@ module I2C_driver (
 
 reg DIR_latched;
 
-reg SDA;
+reg SDA; // TODO make SDA_output a reg and rename everything
 
 assign SDA_output=SDA;
 
@@ -181,8 +181,6 @@ always @(posedge clock) begin
 		6'b010110:begin
 			SCL<=1;
 			if(DIR_latched==1'b1)begin
-				//i2c_data_read[15:0]<={8'h0,SDA_input,i2c_data_read[7:1]};
-
 				i2c_data_read[15:0]<={8'h0,i2c_data_read[6:0],SDA_input};
 			end
 			i2c_state<=6'b010111;
@@ -197,12 +195,21 @@ always @(posedge clock) begin
 		end
 	/****** Acknowledge ********/
 		6'b011000:begin
-			SDA_direction<=0;
+			// Note: If we read we want to send an ack,
+			//       If we write we want to read an ack so it's reversed here
+			if(DIR_latched==1'b1)begin
+				SDA_direction<=1;
+			end else begin
+				SDA_direction<=0;
+			end
 			SCL<=0;
 			i2c_state<=6'b011001;
 		end
 		6'b011001:begin
 			SCL<=0;
+			if(DIR_latched==1'b1)begin
+				SDA<=1'b0;
+			end
 			i2c_state<=6'b011010;
 		end
 		6'b011010:begin
@@ -211,13 +218,12 @@ always @(posedge clock) begin
 		end
 		6'b011011:begin
 			SCL<=1;
-			if (SDA_input==0||ignore_ack==1'b1)begin
+			if (SDA_input==0||DIR_latched==1'b1)begin
 				if(trans_width_latch==1'b1)begin
 					i2c_state<=6'b100101;
 					data_bit_counter<=4'd0;
 				end else
 					i2c_state<=6'b011100;
-				SDA_direction<=1;
 			end else begin
 				i2c_state<=6'b111111;
 			end
@@ -225,18 +231,27 @@ always @(posedge clock) begin
 	/****** Send data (16bit) ********/
 		6'b100101:begin
 			SCL<=0;
-			SDA_direction<=1;
+			if(DIR_latched==1'b1)begin
+				SDA_direction<=0;
+			end else begin
+				SDA_direction<=1;
+			end
 			i2c_state<=6'b100110;
 		end
 		6'b100110:begin
 			SCL<=0;
-			SDA<=data_internal[15:15];
+			if(DIR_latched==1'b0)begin
-			data_internal[15:8]<={data_internal[14:8],1'b0};
+				SDA<=data_internal[15:15];
+				data_internal[15:8]<={data_internal[14:8],1'b0};
+			end
 			data_bit_counter<=data_bit_counter+1;
 			i2c_state<=6'b100111;
 		end
 		6'b100111:begin
 			SCL<=1;
+			if(DIR_latched==1'b1)begin
+				i2c_data_read[15:0]<={i2c_data_read[14:8],SDA_input,i2c_data_read[7:0]};
+			end
 			i2c_state<=6'b101000;
 		end
 		6'b101000:begin