Programmable unit with a stack buffer storage device configurable into discrete shadow storage elements accessible by a plurality of command execution units

Abstract

A programmable unit includes a command execution unit for carrying out commands, a memory device for storing data required for command execution and data emitted from the command execution unit, and a buffer-storage device for buffer storing the data emitted from the command execution unit. The command execution unit writes to the buffer-storage device data to be transferred to the memory device. The data written to the buffer storage device is transferred to the memory device at a later time. The programmable unit is distinguished by forming the buffer-storage device as a stack, and/or by providing a control apparatus that, when required, causes data stored in the buffer-storage device to be moved temporarily to another memory device. Such a programmable unit can carry out any buffer storage of events that may possibly be required quickly and easily in all circumstances.