Context switching with automatic saving of special function registers memory-mapped to all banks
First Claim
1. A microprocessor or microcontroller device comprising:
- a central processing unit (CPU);
a data memory coupled with the CPU, wherein the data memory is divided into a plurality of memory banks; and
a plurality of special function registers that are memory-mapped to the data memory, wherein a first set of special function registers from said plurality of memory-mapped special function registers is memory-mapped to all memory banks; and
wherein upon occurrence of a context switch, the CPU is operable to automatically save the content of the first set of special function registers into a second set of special function registers from said plurality of memory-mapped special function registers and upon return from said context switch restore the content of the first set of special function registers from the second set of special function registers.
15 Assignments
0 Petitions
Accused Products
Abstract
A microcontroller device has a central processing unit (CPU); a data memory coupled with the CPU divided into a plurality of memory banks, a plurality of special function registers and general purpose registers which may be memory-mapped, wherein at least the following special function registers are memory-mapped to all memory banks: a status register, a bank select register, a plurality of indirect memory address registers, a working register, and a program counter high latch; and wherein upon occurrence of a context switch, the CPU is operable to automatically save the content of the status register, the bank select register, the plurality of indirect memory address registers, the working register, and the program counter high latch, and upon return from the context switch restores the content of the status register, the bank select register, the plurality of indirect memory address registers, the working register, and the program counter high latch.
-
Citations
16 Claims
-
1. A microprocessor or microcontroller device comprising:
-
a central processing unit (CPU); a data memory coupled with the CPU, wherein the data memory is divided into a plurality of memory banks; and a plurality of special function registers that are memory-mapped to the data memory, wherein a first set of special function registers from said plurality of memory-mapped special function registers is memory-mapped to all memory banks; and wherein upon occurrence of a context switch, the CPU is operable to automatically save the content of the first set of special function registers into a second set of special function registers from said plurality of memory-mapped special function registers and upon return from said context switch restore the content of the first set of special function registers from the second set of special function registers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method of operating a microprocessor or microcontroller device comprising a central processing unit (CPU);
- a data memory coupled with the CPU, wherein the data memory is divided into a plurality of memory banks;
a plurality of special function registers that are memory-mapped to the data memory, the method comprising the steps of;memory-mapping a first set of special function registers from said plurality of memory-mapped special function registers to all memory banks; upon occurrence of a context switch, saving automatically the content of the first set of special function registers into a second set of special function registers from said plurality of memory-mapped special function registers, and upon return from said context switch restoring the content of the first set of special function registers from the second set of special function registers. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
- a data memory coupled with the CPU, wherein the data memory is divided into a plurality of memory banks;
Specification