Detection mode functionality

STAP08DP05

20/28

DocID024305 Rev 6

10.2

Phase two: “error detection mode“

The eight data bits must be set to “1” in order to set ON all the outputs during detection. The

data are latched by LE/DM1 and after that the outputs are ready for the detection process.

When the microcontroller switches OE/DM2 to LOW, the device drives the LEDs in order to

analyze if an OPEN or SHORT condition has occurred.

The status of the LEDs will be detected in 1 microsecond (minimum) and after this time the

microcontroller sets OE\DM2 in HIGH state and the output data detection result will go to the

microprocessor via SDO.

Detection mode and normal mode both use the same data format. As soon as all the

detection data bits are available on the serial line, the device may go back to normal mode

of operation. To re-detect the status, the device must go back in normal mode and re-enter

error detection mode.

Figure 18. Detection diagram