/*
          file: chop.c
       project: oLogic
   description: Chop line display mode (staircase)
   written by : Michael Bradley

   Changelog:
      08/01/09 separate chop/alt source files
      
*/

void showTracesChop(void)
{
     output_c(TRACE_FLOOR); // create trace floor (10/01/08)
     delay_us(traceWidth); //v1.1 not needed, overhead before loop works fine

     tracePos = TRACE_BEGIN;
     portData = input_b();   // read data from port B

     output_high(SYNC_OUT);

     for (bitTest=0; bitTest < showTraces; bitTest++)
       {
       traceData = 0;
       // v1.1 by testing bit 0, instead of bitTest, then >>1 data
       // we reduced decreased loop time in half
       if (bit_test(portData,0) == 1){
         traceData = TRACE_HEIGHT;
         }
       portData = portData >> 1;
       // v1.1 buy passing the addition in the output_c, saved 10uS
       output_c(tracePos + traceData);
       delay_us(traceWidth);
       tracePos += TRACE_SPACING;
       }


     output_low(SYNC_OUT);
}