In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Zoot wrote:

It's probably the translation, but the datasheet seems a bit unclear. *My* reading, correct me if I'm wrong here, is that ABCD choose which rows are illuminated and this is scanned as a bitmap (i.e. only one bit enabled at a time). The shifted data is the "led on/off" data.

The datasheet specifies a min. scan rate for ABCD. What I'm not clear on is do the rows need to be scanned to save current and because that's how the board is? Seems like you can't/are not supposed to enable all 16 rows at once.

So, I *think* the INTERRUPT needs to handle enabled each row in turn:

[code]
rowEnabled VAR Word

INTERRUPT 1000
   IF rowEnabled = 0 THEN
       rowEnabled = %0000_0000_0000_0001
   ELSE
       rowEnabled = rowEnabled << 1 ' shift left
   ENDIF
RETURNINT
[/code]

Then you should be able shift out what you want independent of the scan enables on the rows, except you might want to dump ALL your bits and latch it all at once. All the registers share the same latch/enable, is that right?

[code]
SUB OUT
  FOR temp1 = 7 to 0 step -1
  SHIFTOUT R1_Dpin, S_Cpin, MSBFIRST, ~pattern1(temp1)' send the bits
  SHIFTOUT R2_Dpin, S_Cpin, MSBFIRST, ~pattern2(temp1)' send the bits
  SHIFTOUT R3_Dpin, S_Cpin, MSBFIRST, ~pattern3(temp1)' send the bits
  SHIFTOUT R4_Dpin, S_Cpin, MSBFIRST, ~pattern4(temp1)' send the bits
  NEXT
  PULSOUT L_Latch, 1                               ' transfer to outputs
ENDSUB
[/code]

I think that would also help minimize ghosting. 

Not sure this helps....

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