User manual

PCL-818 Series User Manual 56
MUX Single-ended/differential channel indicator
0 8 differential channels
1 16 single-ended channels
INT Data valid
0 No A/D conversion has been completed since the last time
the INT bit was cleared. Values in the A/D data registers are
not valid data.
1 The A/D conversion has finished, and converted data is
ready. If the INTE bit of the control register (BASE +09H)
is set, an interrupt signal will be sent to the PC bus through
interrupt level IRQn, where n is specified by bits I2, I1 and
I0 of the control register. Though the A/D status register is
read-only, writing to it with any value will clear the INT bit.
CN3 to CN0 When EOC = 0, these status bits contain the channel number
of the next channel to be converted.
EOC can equal 0 in two different situations: the conversion has com-
pleted or no conversion has been started. Your software should therefore
wait for the signal INT = 1 before it reads the conversion data. It should
then clear the INT bit by writing any value to the A/D status register
BASE+08H.
Note: This bit is used for PCL-818L.
Note: If you trigger the A/D conversion with the on-
board pacer or an external pulse, your software
should check the INT bit, not the EOC bit, before
it reads the conversion data.