80 column mode, scanline timing debugging

src/CMakeLists.txt

@@ -6,6 +6,9 @@ add_executable(${PROGRAM})
 
 target_sources(${PROGRAM} PRIVATE main.c palette.c clocks.pio.h)
 
+# generate image array source files from png images
+visrealm_generate_image_source_ram(${PROGRAM} splash res/splash.png )
+
 # generate header file from pio
 pico_generate_pio_header(${PROGRAM} ${CMAKE_CURRENT_LIST_DIR}/clocks.pio)
 

src/main.c

@@ -16,6 +16,8 @@
 
 #include "palette.h"
 
+#include "splash.h"
+
 #include "vrEmuTms9918Util.h"
 
 #include "pico/stdlib.h"
@@ -67,15 +69,22 @@
 #define GPIO_INT 22
 #define GPIO_GROMCL 29
 #define GPIO_CPUCL 23
+#define GPIO_LED 25
 
 #define GPIO_CD_MASK (0xff << GPIO_CD0)
 #define GPIO_CSR_MASK (0x01 << GPIO_CSR)
 #define GPIO_CSW_MASK (0x01 << GPIO_CSW)
 #define GPIO_MODE_MASK (0x01 << GPIO_MODE)
 #define GPIO_INT_MASK (0x01 << GPIO_INT)
+#define GPIO_LED_MASK (0x01 << GPIO_LED)
 
 #define TMS_CRYSTAL_FREQ_HZ 10738635.0f
 
+#define GPIO_CD_REVERSED 1
+#define LED_BLINK_ON_WRITE 1
+
+
+#if GPIO_CD_REVERSED
 
   /* In revision 0.2 of my prototype PCB, CD0 through CD7 are inconveniently reversed into the
      Pi Pico GPIO pins. Quickest way to deal with that is this lookup table.
@@ -101,9 +110,12 @@ static uint8_t  __aligned(4) reversed[] =
   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
 };
+#define REVERSE(x) reversed[x]
+#else
+#define REVERSE(x) x
+#endif
 
-
-/* file globals */
+  /* file globals */
 
 static VrEmuTms9918* tms = NULL;  /* our vrEmuTms9918 instance handle */
 static uint32_t nextValue = 0; /* TMS9918A read-ahead value */
@@ -128,7 +140,7 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
 
     if (gpios & GPIO_MODE_MASK) /* read status register */
     {
-      sio_hw->gpio_out = ((uint32_t)reversed[vrEmuTms9918ReadStatus(tms)] << GPIO_CD0) | GPIO_INT_MASK;
+      sio_hw->gpio_out = ((uint32_t)REVERSE(vrEmuTms9918ReadStatus(tms)) << GPIO_CD0) | GPIO_INT_MASK;
       currentInt = GPIO_INT_MASK;
     }
     else /* read data */
@@ -139,7 +151,7 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
   }
   else if ((gpios & GPIO_CSW_MASK) == 0)  /* write? */
   {
-    uint8_t value = reversed[(sio_hw->gpio_in >> GPIO_CD0) & 0xff];
+    uint8_t value = REVERSE((sio_hw->gpio_in >> GPIO_CD0) & 0xff);
 
     if (gpios & GPIO_MODE_MASK) /* write register/address */
     {
@@ -151,15 +163,20 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
     else /* write data */
     {
       vrEmuTms9918WriteData(tms, value);
+
+#if LED_BLINK_ON_WRITE
+      sio_hw->gpio_out = GPIO_LED_MASK | currentInt;
+#endif
     }
   }
   else /* both CSR and CSW are high (inactive). Go High-Z */
   {
     sio_hw->gpio_oe_clr = GPIO_CD_MASK;
+    sio_hw->gpio_out = currentInt;
   }
 
   /* update read-ahead */
-  nextValue = reversed[vrEmuTms9918ReadDataNoInc(tms)] << GPIO_CD0;
+  nextValue = REVERSE(vrEmuTms9918ReadDataNoInc(tms)) << GPIO_CD0;
 
   /* interrupt handled */
   iobank0_hw->intr[GPIO_CSR >> 3u] = iobank0_hw->proc1_irq_ctrl.ints[GPIO_CSR >> 3u];
@@ -171,9 +188,9 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
 void proc1Entry()
 {
   // set up gpio pins
-  gpio_init_mask(GPIO_CD_MASK | GPIO_CSR_MASK | GPIO_CSW_MASK | GPIO_MODE_MASK | GPIO_INT_MASK);
+  gpio_init_mask(GPIO_CD_MASK | GPIO_CSR_MASK | GPIO_CSW_MASK | GPIO_MODE_MASK | GPIO_INT_MASK | GPIO_LED_MASK);
   gpio_put_all(GPIO_INT_MASK);
-  gpio_set_dir_all_bits(GPIO_INT_MASK); // int is an output
+  gpio_set_dir_all_bits(GPIO_INT_MASK | GPIO_LED_MASK); // int is an output
 
   // ensure CSR and CSW are high (inactive)
   while (!gpio_get(GPIO_CSW) || !gpio_get(GPIO_CSR))
@@ -196,7 +213,7 @@ void proc1Entry()
 static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uint16_t* pixels)
 {
   const uint32_t vBorder = (params->vVirtualPixels - TMS9918_PIXELS_Y) / 2;
-  const uint32_t hBorder = (params->hVirtualPixels - TMS9918_PIXELS_X) / 2;
+  const uint32_t hBorder = (params->hVirtualPixels - TMS9918_PIXELS_X * 2) / 2;
 
   uint16_t bg = tms9918PaletteBGR12[vrEmuTms9918RegValue(tms, TMS_REG_FG_BG_COLOR) & 0x0f];
 
@@ -207,6 +224,30 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
     {
       pixels[x] = bg;
     }
+
+
+    /* source: C:/Users/troy/OneDrive/Documents/projects/pico9918/src/res/splash.png
+     * size  : 172px x 10px
+     *       : 3440 bytes
+     * format: 16bpp abgr image
+     */
+    if (y >= vBorder + TMS9918_PIXELS_Y + 12)
+    {
+      y -= vBorder + TMS9918_PIXELS_Y + 12;
+      if (y < 10)
+      {
+        uint16_t* splashPtr = splash + (y * 172);
+        for (int x = 4; x < 4 + 172; ++x)
+        {
+          uint16_t c = *(splashPtr++);
+          if (c & 0xf000)
+          {
+           pixels[x] = c;
+          }
+        }
+      }
+    }
+
     return;
   }
 
@@ -225,13 +266,24 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
 
   /* convert from tms palette to bgr12 */
   int tmsX = 0;
-  for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X; ++x, ++tmsX)
+  if (tmsScanlineBuffer[0] & 0xf0)
   {
-    pixels[x] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX]];
+    for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X * 2; x += 2, ++tmsX)
+    {
+      pixels[x] = tms9918PaletteBGR12[(tmsScanlineBuffer[tmsX] & 0xf0) >> 4];
+      pixels[x + 1] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX] & 0x0f];
+    }
+  }
+  else
+  {
+    for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X * 2; x += 2, ++tmsX)
+    {
+      pixels[x] = pixels[x + 1] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX] & 0x0f];
+    }
   }
 
   /*** right border ***/
-  for (int x = hBorder + TMS9918_PIXELS_X; x < params->hVirtualPixels; ++x)
+  for (int x = hBorder + TMS9918_PIXELS_X * 2; x < params->hVirtualPixels; ++x)
   {
     pixels[x] = bg;
   }
@@ -246,9 +298,6 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
 
 /*
  * initialise a clock output using PIO
- *
- * GROMCLK is crystal frequency / 24 (~447KHz)
- * CPUCLK is crystal frequency / 3 (~3.58MHz)
  */
 uint initClock(uint gpio, float freqHz)
 {
@@ -295,8 +344,14 @@ int main(void)
 
   /* then set up VGA output */
   VgaInitParams params = { 0 };
-  params.params = vgaGetParams(VGA_640_480_60HZ, 2);
+  params.params = vgaGetParams(VGA_640_480_60HZ);
+
+  /* virtual size will be 640 x 320 to accomodate 80-column mode */
+  setVgaParamsScaleY(&params.params, 2);
+
+  /* set vga scanline callback to generate tms9918 scanlines */
   params.scanlineFn = tmsScanline;
+
   vgaInit(params);
 
   /* signal proc1 that we're ready to start the display */

src/vga/vga-modes.c

@@ -16,10 +16,8 @@ void vgaUpdateTotalPixels(VgaSyncParams* params);
 /*
  * populate VgaParams for known vga modes
  */
-VgaParams vgaGetParams(VgaMode mode, int pixelScale)
+VgaParams vgaGetParams(VgaMode mode)
 {
-  if (pixelScale < 1) pixelScale = 1;
-
   VgaParams params;
 
   switch (mode)
@@ -112,14 +110,44 @@ VgaParams vgaGetParams(VgaMode mode, int pixelScale)
     params.vSyncParams.freqHz = 1.0f / frameTimeSeconds;
   }
 
-  params.hPixelScale = pixelScale;
-  params.vPixelScale = pixelScale;
-  params.hVirtualPixels = (params.hSyncParams.displayPixels / params.hPixelScale);
-  params.vVirtualPixels = (params.vSyncParams.displayPixels / params.vPixelScale);
+  setVgaParamsScale(&params, 1);
 
   return params;
 }
 
+/*
+ * set the scale/multiplier of virtual pixel size
+ */
+bool setVgaParamsScale(VgaParams* params, int pixelScale)
+{
+  return setVgaParamsScaleX(params, pixelScale) &&
+    setVgaParamsScaleY(params, pixelScale);
+}
+
+bool setVgaParamsScaleXY(VgaParams* params, int pixelScaleX, int pixelScaleY)
+{
+  return setVgaParamsScaleX(params, pixelScaleX) &&
+    setVgaParamsScaleY(params, pixelScaleY);
+}
+
+bool setVgaParamsScaleX(VgaParams* params, int pixelScale)
+{
+  if (!params || pixelScale < 1) return false;
+
+  params->hPixelScale = pixelScale;
+  params->hVirtualPixels = (params->hSyncParams.displayPixels / params->hPixelScale);
+  return true;
+}
+
+bool setVgaParamsScaleY(VgaParams* params, int pixelScale)
+{
+  if (!params || pixelScale < 1) return false;
+
+  params->vPixelScale = pixelScale;
+  params->vVirtualPixels = (params->vSyncParams.displayPixels / params->vPixelScale);
+  return true;
+}
+
 /*
  * update total number of pixels
  */

src/vga/vga-modes.h

@@ -22,4 +22,16 @@ typedef enum
   VGA_1280_1024_60HZ,
 } VgaMode;
 
-extern VgaParams vgaGetParams(VgaMode mode, int pixelScale);
+
+/*
+ * get the vga parameters for known modes
+ */
+VgaParams vgaGetParams(VgaMode mode);
+
+/*
+ * set the scale/multiplier of virtual pixel size
+ */
+bool setVgaParamsScale(VgaParams* params, int pixelScale);
+bool setVgaParamsScaleXY(VgaParams* params, int pixelScaleX, int pixelScaleY);
+bool setVgaParamsScaleX(VgaParams* params, int pixelScale);
+bool setVgaParamsScaleY(VgaParams* params, int pixelScale);