Added lots of comments. Doxygen tags are still needed.

1 files changed, 97 insertions, 5 deletions

diff --git a/Graphic_Equalizer/src/smartmedia.hcc b/Graphic_Equalizer/src/smartmedia.hcc
index e87c852..f52db79 100644
--- a/Graphic_Equalizer/src/smartmedia.hcc
+++ b/Graphic_Equalizer/src/smartmedia.hcc
@@ -46,10 +46,15 @@
 unsigned 1 smartmedia_init(void) {

 	unsigned 1 retval;

 	/*

-	 * Firstly we enable both the CPLD and the SmartMedia.

+	 * Firstly we enable both the CPLD.

 	 */

 	RC200CPLDEnable();

 

+	/*

+	 * We must reset the Smart Media before initializing it. If we don't reset it

+	 * we get a lot of Init failures. If we don't use the delay, we get a lot of

+	 * init failures.

+	 */

 	RC200SmartMediaReset(&retval);

 	delay;

 	RC200SmartMediaInit(&retval);

@@ -70,6 +75,11 @@ unsigned 1 smartmedia_init(void) {
 void smartmedia_loaddata(skindata_t *skindata) {

 	/*

 	 * Setup RAM Handle, and determin maximum Data and Address widths

+	 *

+	 * FIXME: Currently we set the Ram handle here and in the main. If we

+	 * would want to change it here, also change it elsewhere. A better

+	 * solution would be to have the RAM_BANK0 macro defined somewhere

+	 * globally.

 	 */

 	macro expr RAM_BANK0 = PalPL2RAMCT(0);

 	macro expr DW = PalPL2RAMGetMaxDataWidthCT();

@@ -85,9 +95,21 @@ void smartmedia_loaddata(skindata_t *skindata) {
 

 	extern ram unsigned 8 presets_default_values[768];

 

+	/*

+	 * Before we enter our main Smart Media read loop we verify the format

+	 * of the SMC. This to ensure we use the correct functions later.

+	 */

 	RC200SmartMediaCheckLogicalFormat(&physical_format);	

 

+	/*

+	 * We have several stages to go through. We stop once we pass the last

+	 * one.

+	 */

 	while ((STAGE_LOAD_ABOUT_BOTTOM +1) != stage) {

+		/*

+		 * For each iteration of the main loop we set a different

+		 * start and end variables.

+		 */

 		switch (stage) {

 			case STAGE_LOAD_DEMO_PRESET:

 				sm_address = SMARTMEDIA_ADDRESS_PRESET_DEMO_START;

@@ -149,29 +171,79 @@ void smartmedia_loaddata(skindata_t *skindata) {
 			default:

 				break;

 		}

+		/*

+		 * TODO: Replace the above switch-case with a lookuptables.

+		 */

 

+		/*

+		 * The only difference between logical and phyiscally formated

+		 * SMCs codewise is how they are addressed.

+		 */

 		if (physical_format) {

 			RC200SmartMediaSetAddress(READ, sm_address);

 		} else {

 			RC200SmartMediaSetLogicalAddress(READ, sm_address);

 		}

 		

+		/*

+		 * While the address hasn't reached the end, continue loading data.

+		 */

 		while (address != address_end) {

 

+			/*

+			 * No matter what we read from the SMC, we aways need to

+			 * read at least one byte per iteration. (Otherwise there

+			 * would be no point in entering this loop.

+			 */

 			RC200SmartMediaRead(&mask, FALSE);

+

+			/*

+			 * The difference when loading data from the SMC is

+			 * when we load the presets. These aren't stored in

+			 * external RAM but in an array on the FPGA.

+			 */

 			if ((STAGE_LOAD_DEMO_PRESET == stage) || (STAGE_LOAD_RESET_PRESET == stage)) {

+				/*

+				 * We only read one byte from the SMC and thus

+				 * we only store one byte. We re-use the 'mask'

+				 * variable here. The address is also re-used

+				 * and thus we only use the last 10 bits to fit

+				 * the address in our index.

+				 *

+				 */

 				presets_default_values[address <- 10] = mask;

 			} else {

+				/*

+				 * There needs to be atleast one clock cycle

+				 * between setting the address and reading

+				 * from it. We therefore set the address before

+				 * reading from the SmartMedia as 'delay'.

+				 */

+				PalPL2RAMSetWriteAddress(RAM_BANK0, address);

+

+				/*

+				 * All other data has RGB image data and thus

+				 * we read those additional bytes from the SMC.

+				 * The image used for the graphic visualization

+				 * is packed together however and thus we

+				 * re-use the rgb variables here.

+				 */

 				RC200SmartMediaRead(&r, FALSE);

 				RC200SmartMediaRead(&g, FALSE);

 				RC200SmartMediaRead(&b, FALSE);

 

-				PalPL2RAMSetWriteAddress(RAM_BANK0, address);

+				/*

+				 * FIXME: Do we need this even?

+				 */

 				data = 0 @ mask @ r @ g @ b;

+

+				/*

+				 * Now that we read a while 32bit wide word

+				 * we can store it in the main memory bank.

+				 */

 				PalPL2RAMWrite(RAM_BANK0, data);

 			}

 

-			address++;

 #if HAVE_DEBUG
 			/*
 			 * Print some indication about data loading.
@@ -180,16 +252,36 @@ void smartmedia_loaddata(skindata_t *skindata) {
 				print_string(".");
 			}
 #endif

+			/*

+			 * Finally we increase our address to prepare for the

+			 * next iteration.

+			 */

+			address++;

 		}

+		/*

+		 * We need to tell the SmartMedia that the last byte was read

+		 * however to check wether it is the last byte during each

+		 * iteration of the loop would unecasserly 'a lot' of

+		 * resources. We therefore read a dummy byte here. It doesn't

+		 * matter where it comes from (from the SMC) as we don't use

+		 * it.

+		 */

 		RC200SmartMediaRead(&mask, TRUE);

+		/*

+		 * Because we need to set a new starting address in the next

+		 * iteration we need to 'end' the SmartMedia Operation.

+		 */

 		RC200SmartMediaOperationEnd(&result);

 

+		/*

+		 * We are done with this 'stage' and continue to the next one.

+		 */

 		stage++;

 	}

 

 	/*

-	 * This block needs to probably move up into the for loop where we

-	 * calculate these settings determind by the image data..

+	 * TODO: This block needs to move up into the loop where we calculate

+	 * these settings determind by the image data.

 	 */

 	skindata->spectrum.top = 200;

 	skindata->spectrum.bottom = 335;