Abstract:

Multitask management unit (MTU) is a test unit which implements multitask management in a protected mode in microprocessors, and provides hardware support for tasks switch in microprocessor level. Firstly, a scheme for MTU is established, based on the scheme tasks switch algorithm given to switch tasks. Secondly, by analyzing the data structure and definition for multitask management, a kind of cell group architecture for MTU is put forward. The architecture consists of cells, each of which processes a kind of test and outputs Boolean value to microprogram controller. So an aim is achieved that the Boolean value of cell test in MTU may control microprogram branch. At last, the VHDL description of RTL level of MTU has been synthesized and simulated successfully in MENTOR GRAPHICS of EDA tools and its results of simulation prove MTU valid.

Key words: multitask management unit ( MTU), task switch, cell, instruction cycle