Differences

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--- ff3:ff3us:doc:snes:register [2019/08/08 02:28]
madsiur [Counter Latch]
+++ ff3:ff3us:doc:snes:register [2019/08/08 02:56]
madsiur [Counter Latch]
@@ Line 69: / Line 69: @@
 |Horizontal Counter Latch  |  [[register#Counter Latch|$213C]]  |  OPHCT  |  dual  |  read  |  any time  |
 |Vertical Counter Latch  |  [[register#Counter Latch|$213D]]  |  OPVCT  |  dual  |  read  |  any time  |
-|PPU Status Register  |  ''$213E''  |  STAT77  |  single  |  read  |  any time  |
+|PPU1 Status and Version Number  |  [[register#PPU1 Status and Version Number|$213E]]  |  STAT77  |  single  |  read  |  any time  |
-|PPU Status Register  |  ''$213F''  |  STAT78  |  single  |  read  |  any time  |
+|PPU2 Status and Version Number  |  [[register#PPU2 Status and Version Number|$213F]]  |  STAT78  |  single  |  read  |  any time  |
 |APU IO Registers  |  ''$2140''  |  APUIO0  |  single  |  both  |  any time  |
 |APU IO Registers  |  ''$2141''  |  APUIO1  |  single  |  both  |  any time  |
@@ Line 827: / Line 827: @@
 [[register#Address Bus B Registers|Back to top]]
+===== PPU1 Status and Version Number =====
+<code>
+$213E r b++++ STAT77 - PPU1 Status and Version Number
+        trmuvvvv
+        t    = OBJ Time overflow  (0=Okay, 1=More than 8x34 OBJ pixels per scanline)
+        r    = OBJ Range overflow (0=Okay, 1=More than 32 OBJs per scanline)
+        m    = Master/Slave Mode (PPU1.Pin25) (0=Normal=Master)
+        u    = unused
+        vvvv = PPU1 5C77 Version Number (only version 1 exists)
+</code>
+Bit t: If more than 34 sprite-tiles (e.g. a 16x16 sprite has 2 sprite-tiles) were encountered on a single line, this flag will be set. The flag is reset at the end of V-Blank but not during forced blank.
+Bit r: If more than 32 sprites were encountered on a single line, this flag will be set. The flag is reset at the end of V-Blank but not during forced blank.
+Note that the above two flags are set whether or not OBJ are actually enabled at the time (see $212C), at the following times: bit 6 when V=OBJ.YLOC/H=OAM.INDEX*2, bit 7 when V=OBJ.YLOC+1/H=0.