The TLC5916/TLC5917 provides a Special Mode in which two functions are included, Error Detection and Current Gain Control. There are two operation modes and three phases: Normal Mode phase, Mode Switching transition phase, and Special Mode phase. The signal on the multiple function pin OE(ED2) is monitored to determine the mode. When an one-clock-wide pulse appears on OE(ED2), the device enters the Mode Switching phase. At this time, the voltage level on LE(ED1) determines the mode to which the TLC5916/TLC5917 switches. In the Normal Mode phase, the serial data can be transferred into TLC5916/TLC5917 via the pin SDI, shifted in the shift register, and transferred out via the pin SDO. LE(ED1) can latch the serial data in the shift register to the output latch. OE(ED2) enables the output drivers to sink current. In the Special Mode phase, the low-voltage-level signal OE(ED2) can enable output channels and detect the status of the output current, to determine if the driving current level is sufficient. The detected Error Status is loaded into the 8-bit shift register and shifted out via the pin SDO, synchronous to the CLK signal. The system controller can read the error status and determine whether or not the LEDs are properly lit. In the Special Mode phase, the TLC5916/TLC5917 allows users to adjust the output current level by setting a runtime-programmable Configuration Code. The code is sent into the TLC5916/TLC5917 via SDI. The positive pulse of LE(ED1) latches the code in the shift register into a built-in 8-bit configuration latch, instead of the output latch. The code affects the voltage at the terminal R-EXT and controls the output-current regulator. The output current can be finely adjusted by a gain ranging from 1/12 to 127/128 in 256 steps. Therefore, the current skew between ICs can be compensated within less than 1%. This feature is suitable for white balancing in LED color display panels.