Data processing system having multiple register contexts and method therefor
AssigneeFreescale Semiconductor, Inc.
InventorsWilliam C. Moyer, John H. Arends
Life of this patent
Estimating the term…
Abstract
A data processing system having multiple register contexts is described. One embodiment of the present invention uses a user programmable context control register for each of the multiple register contexts to allow for the mapping of portions of an alternate register context into a current register context. The context control register may also be used to provide for the sharing of common stack pointers among multiple register contexts. Therefore, when operating in a current register context, the context control register may be used to access portions of an alternate register context in place of accessing corresponding portions of the current register context.
Claims21
A data processing system comprising:
- a plurality of register contexts;
- storage circuitry for storing context control information corresponding to at least a portion of the plurality of register contexts, wherein the storage circuitry comprises a plurality of context control registers, wherein each of the plurality of register contexts comprises a corresponding context control register;
- and
- processing circuitry for selectively accessing a portion of an alternate register context within the plurality of register contexts in place of a corresponding portion of a current register context within the plurality of register contexts, wherein the alternate register context and the portion of the alternate register context are indicated by the context control register corresponding to the current register context;
- and wherein the context control register corresponding to the current register context comprises a mapping field to identify the portion of the alternate register context and an alternate context field to identify the alternate register context.
In a data processing system having a plurality of register contexts, a method comprising:
- operating in a first register context within the plurality of register contexts, each of the plurality of register contexts having corresponding context control information, wherein operating in the first register context comprises:
- accessing a first portion of the first register context;
- selectively accessing a portion of a second register context corresponding to a second portion of the first register context based on the corresponding context control information of the first register context, wherein the corresponding context control information of the first register context identifies the second register context and the portion of the second register context;
- and wherein each of the corresponding context control information comprises a mapping field to identify the portion of the second register context and an alternate context field to identify the second register context.
A data processing system comprising:
- a plurality of register contexts, wherein each register context comprises a corresponding context control register having an alternate register context field and a mapping field;
- and
- processing means for selectively accessing a portion of an alternate register context within the plurality of register contexts in place of accessing a corresponding portion of a current register context within the plurality of register contexts, wherein the portion of the alternate register context is defined by the mapping field in the context control register corresponding to the current register context and the alternate register context is defined by the alternate register context field in the context control register corresponding to the current register context.
Dependencies are inferred from the claim text.