vdp fifo, refined timing

diff --git a/pico/videoport.c b/pico/videoport.c
index 122908e..fb6bd69 100644 (file)
--- a/pico/videoport.c
+++ b/pico/videoport.c
@@ -2,6 +2,7 @@
  * PicoDrive\r
  * (c) Copyright Dave, 2004\r
  * (C) notaz, 2006-2009\r
+ * (C) kub, 2020\r
  *\r
  * This work is licensed under the terms of MAME license.\r
  * See COPYING file in the top-level directory.\r
@@ -58,38 +59,38 @@ static const int vdpsl2cyc_bl[] = { (488<<16)/166, (488<<16)/204 };
 \r
 // VDP transfer slots in active display 32col mode. 1 slot is 488/171 = 2.8538\r
 // 68k cycles. Only 16 of the 171 slots in a scanline can be used by CPU/DMA:\r
-// (HINT=slot 0): 13,27,42,50,58,74,82,90,106,114,122,138,146,154,169,170\r
+// (HINT=slot 0): 11,25,40,48,56,72,80,88,104,112,120,136,144,152,167,168\r
 static const unsigned char vdpcyc2sl_32[] = { // 68k cycles/4 to slot #\r
 //  4  8 12 16 20 24 28 32 36 40 44 48 52 56 60\r
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1,\r
- 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3,\r
- 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,\r
- 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7,\r
- 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9,\r
- 9,10,10,10,10,10,10,11,11,11,11,11,11,11,11,11,\r
-11,11,12,12,12,12,12,12,13,13,13,13,13,13,14,14,\r
-14,14,14,14,14,14,14,14,15,16,16,16,16,16,16,16,\r
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,\r
+ 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3,\r
+ 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5,\r
+ 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8,\r
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9,10,\r
+10,10,10,10,10,11,11,11,11,11,11,11,11,11,11,11,\r
+11,12,12,12,12,12,13,13,13,13,13,13,14,14,14,14,\r
+14,14,14,14,14,14,14,15,16,16,16,16,16,16,16,16,\r
 };\r
 static const unsigned char vdpsl2cyc_32[] = { // slot # to 68k cycles/4\r
-  0,  9, 19, 30, 35, 41, 52, 58, 64, 75, 81, 87, 98,104,110,120,121,131\r
+  0,  8, 18, 28, 33, 39, 51, 56, 62, 74, 79, 85, 97,102,108,119,120,130\r
 };\r
 \r
 // VDP transfer slots in active display 40col mode. 1 slot is 488/210 = 2.3238\r
 // 68k cycles. Only 18 of the 210 slots in a scanline can be used by CPU/DMA:\r
-// (HINT=0): 23,49,57,65,81,89,97,113,121,129,145,153,161,177,185,193,208,209\r
+// (HINT=0): 21,47,55,63,79,87,95,111,119,127,143,151,159,175,183,191,206,207,\r
 static const unsigned char vdpcyc2sl_40[] = { // 68k cycles/4 to slot #\r
 //  4  8 12 16 20 24 28 32 36 40 44 48 52 56 60\r
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,\r
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2,\r
- 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5,\r
- 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7,\r
- 7, 8, 8, 8, 8, 8, 9, 9, 9, 9,10,10,10,10,10,10,\r
-10,10,10,10,11,11,11,11,12,12,12,12,12,13,13,13,\r
-13,13,13,13,13,13,14,14,14,14,14,15,15,15,15,15,\r
-16,16,16,16,16,16,16,16,17,18,18,18,18,18,18,18,\r
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1,\r
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,\r
+ 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5,\r
+ 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7,\r
+ 8, 8, 8, 8, 8, 9, 9, 9, 9,10,10,10,10,10,10,10,\r
+10,10,10,11,11,11,11,12,12,12,12,12,13,13,13,13,\r
+13,13,13,13,13,14,14,14,14,14,15,15,15,15,15,16,\r
+16,16,16,16,16,16,16,17,18,18,18,18,18,18,18,18,\r
 };\r
 static const unsigned char vdpsl2cyc_40[] = { // slot # to 68k cycles/4\r
-  0, 13, 28, 33, 37, 47, 51, 56, 65, 70, 74, 84, 88, 93,102,107,112,120,121,135\r
+  0, 12, 27, 32, 36, 46, 50, 55, 64, 69, 73, 83, 87, 92,101,106,111,119,120,134\r
 };\r
 \r
 // NB code assumes fifo_* arrays have size 2^n\r
@@ -164,7 +165,7 @@ static __inline void SetFIFOState(struct PicoVideo *pv)
   if (fifo_total <= 4) {\r
     int x = (fifo_qx + fifo_ql - 1) & 7;\r
     if ((pv->status & SR_DMA) && !(pv->status & PVS_DMAFILL) &&\r
-                fifo_ql && !(fifo_queue[x] & FQ_BGDMA)) {\r
+                (!fifo_ql || !(fifo_queue[x] & FQ_BGDMA))) {\r
       pv->status &= ~SR_DMA;\r
       pv->command &= ~0x80;\r
     }\r
@@ -263,7 +264,7 @@ int PicoVideoFIFOWrite(int count, int flags, unsigned sr_mask,unsigned sr_flags)
   if (count && fifo_ql < 8) {\r
     // update FIFO state if it was empty\r
     if (fifo_ql == 0) {\r
-      fifo_slot = GetFIFOSlot(pv, lc+10); // FIFO latency ~4 vdp slots\r
+      fifo_slot = GetFIFOSlot(pv, lc+9); // FIFO latency ~3 vdp slots\r
       pv->fifo_cnt = count << (flags & FQ_BYTE);\r
     }\r
 \r
@@ -340,7 +341,7 @@ static __inline void AutoIncrement(void)
 static __inline void UpdateSAT(u32 a, u32 d)\r
 {\r
   Pico.est.rendstatus |= PDRAW_DIRTY_SPRITES;\r
-  if (!((a^sat) >> satxbits) && !(a & 4)) {\r
+  if (!(a & 4)) {\r
     int num = (a-sat) >> 3;\r
     ((u16 *)&VdpSATCache[num])[(a&3) >> 1] = d;\r
   }\r
@@ -672,7 +673,6 @@ static NOINLINE void CommandDma(void)
              fifo_total, SekPc);\r
     fifo_total = fifo_ql = 0;\r
   }\r
-  pvid->status |= SR_DMA;\r
 \r
   len = GetDmaLength();\r
   source =Pico.video.reg[0x15];\r
@@ -685,7 +685,7 @@ static NOINLINE void CommandDma(void)
   else if (method == 3)\r
     DmaCopy(len); // VRAM Copy\r
   else {\r
-    pvid->status |= PVS_DMAFILL;\r
+    pvid->status |= SR_DMA|PVS_DMAFILL;\r
     return;\r
   }\r
   source += len;\r
@@ -747,7 +747,7 @@ PICO_INTERNAL_ASM void PicoVideoWrite(unsigned int a,unsigned short d)
         !(!pvid->pending &&\r
           ((pvid->command & 0xc00000f0) == 0x40000010 && PicoMem.vsram[pvid->addr>>1] == (d & 0x7ff)))\r
        )\r
-      DrawSync(SekCyclesDone() - Pico.t.m68c_line_start <= 488-440);\r
+      DrawSync(0); // XXX  it's unclear when vscroll data is fetched from vsram?\r
 \r
     if (pvid->pending) {\r
       CommandChange();\r
@@ -902,8 +902,8 @@ update_irq:
 static u32 VideoSr(const struct PicoVideo *pv)\r
 {\r
   unsigned int c, d = pv->status;\r
-  unsigned int hp = pv->reg[12]&1 ? 32:40; // HBLANK start\r
-  unsigned int hl = pv->reg[12]&1 ? 94:84; // HBLANK length\r
+  unsigned int hp = pv->reg[12]&1 ? 15*488/210+1 : 15*488/171+1; // HBLANK start\r
+  unsigned int hl = pv->reg[12]&1 ? 37*488/210+1 : 28*488/171+1; // HBLANK len\r
 \r
   c = SekCyclesDone() - Pico.t.m68c_line_start;\r
   if (c - hp < hl)\r
@@ -1013,7 +1013,9 @@ unsigned char PicoVideoRead8HV_H(void)
 unsigned char PicoVideoRead8HV_L(void)\r
 {\r
   u32 d = (SekCyclesDone() - Pico.t.m68c_line_start) & 0x1ff; // FIXME\r
-  if (Pico.video.reg[12]&1)\r
+  if (Pico.video.reg[0]&2)\r
+       d = Pico.video.hv_latch;\r
+  else if (Pico.video.reg[12]&1)\r
        d = hcounts_40[d];\r
   else d = hcounts_32[d];\r
   elprintf(EL_HVCNT, "hcounter: %02x [%u] @ %06x", d, SekCyclesDone(), SekPc);\r