The sequencer (see figure Memory Management Block Diagram) controls the program counter and is one of the most important blocks. The inputs to the sequencer are the control memory, 16 bit registers (A, B, C, D, P and T) and the 16 external events input lines, through the comparators.
Each program step includes one command residing in the control memory. Sequencer commands allow you to control and manipulate the program counter. Each memory step can include only one sequencer command. Most of these commands can be conditioned.