16.2 MICROINSTRUCTION SEQUENCING
The two basic tasks performed by a microprogrammed control unit are as follows:
• Microinstruction sequencing: Get the next microinstruction from the control
memory.
• Microinstruction execution: Generate the control signals needed to execute
the microinstruction.
In designing a control unit, these tasks must be considered together, because
both affect the format of the microinstruction and the timing of the control unit. In
this section, we will focus on sequencing and say as little as possible about format
and timing issues.These issues are examined in more detail in the next section.