发明名称 Saturation detector
摘要 A hardware integer saturation detector that detects both whether packing a 32-bit integer value causes saturation and whether packing each of first and second 16-bit integer values causes saturation, where the first 16-bit integer value is the upper 16 bits of the 32-bit integer value and the second 16-bit integer value is the lower 16 bits of the 32-bit integer value. The detector includes hardware signal logic, configured to generate four signals with information about the integer values. The hardware integer detector also includes saturation logic, configured to gate the four signals to generate a saturation signal. Each bit of the saturation signal indicates whether packing the 32-bit integer value or whether packing one of the first and second 16-bit integer values will cause saturation respectively.
申请公布号 US8849885(B2) 申请公布日期 2014.09.30
申请号 US201213491260 申请日期 2012.06.07
申请人 Via Technologies, Inc. 发明人 Glover Clinton Thomas
分类号 G06F7/499 主分类号 G06F7/499
代理机构 代理人 Davis E. Alan;Huffman James W.;Davis Michael B.
主权项 1. A hardware integer saturation detector, configured to detect whether packing a 32-bit integer value causes saturation and whether packing each of first and second 16-bit integer values causes saturation, wherein the first 16-bit integer value is the upper 16 bits of the 32-bit integer value and the second 16-bit integer value is the lower 16 bits of the 32-bit integer value, the hardware integer saturation module comprising: hardware signal logic, configured to generate: a 3-bit signal A that indicates whether a most significant bit of the 32-bit integer value and a most significant bit of each of the first and second 16-bit integer values is a 0 or a 1;a 3-bit signal B that indicates whether a most significant bit of a least significant word of the 32-bit integer value and whether a most significant bit of a least significant byte of each of the first and second 16-bit integer values is a 0 or a 1;a 3-bit signal C that indicates whether a most significant word of the 32-bit integer value is equal to 0xFFFF and whether a most significant byte of each of the first and second 16-bit integer values is equal to 0xFF; anda 3-bit signal D that indicates whether a most significant word of the 32-bit integer value is equal to 0x0000 and whether a most significant byte of each of the first and second 16-bit integer values is equal to 0x00; and hardware saturation logic, configured to: NAND the bits of signal B with the bits of signal C to form a signal E;NAND the bits of signal D with the inverted bits of signal B to form a signal F;MUX between the bits of signal E and signal F using the bits of signal A as control signals to form a signal J;MUX between signal J and an inverted signal D to form a 3-bit saturation signal, using a signal that indicates whether the packing operation is signed or unsigned as a control signal.
地址 New Taipei TW