Data processing apparatus with improved bit masking capability

摘要: A graphics processor device is disclosed which performs bit-by-bit masking outside of the central processing unit, by way a read-modify-write cycle to external or internal memory. mask bus incorporated into so that, for each bit data word, present indicates whether from unit (CPU) be written memory (unmasked) if that contents remain unaltered (masked). The CPU latch at interface during such time as isolated and read portion cycle. For those bits are masked, overwritten with memory, while unmasked remains bus. During write cycle, driven onto may also done in multiplexing