# System Information Block

The System Information Block (SIB) can be read out at any time by setting the SIB bit according to the KEY instruction from KEY - Set Activation Key or Send System Information Block. The SIB is always accessible to the debugger, regardless of lock bit settings, and provides a compact form of supplying information about the device and system parameters for the debugger. The information is vital in identifying and setting up the proper communication channel with the device. The output of the SIB is interpreted as ASCII symbols. The key size field must be set to 16 bytes when reading out the complete SIB, and an 8-byte size can be used to read out only the Family_ID. See Figure 1 for SIB format description and which data are available at different readout sizes.
Figure 1. System Information Block Format