S3C2440A RISC MICROPROCESSOR THUMB INSTRUCTION SET
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4 THUMB INSTRUCTION SET

THUMB INSTRUCTION SET FORMAT

The thumb instruction sets are 16-bit versions of ARM instruction sets (32-bit format). T he ARM instructions are
reduced to 16-bit versions.Thumb instructions, at the cost of versatile functions of the ARM instruction sets . The
thumb instructions are decompressed to the ARM instructions by the Thumb decompr essor inside the ARM920T
core.
As the Thumb instructions are compressed ARM instructions, the Thum b instructions have the 16-bit format
instructions and have some restrictions. The restriction by 16-bit format is fully notified for using the Thumb
instructions.