| 摘要 |
A computer system module includes a central processing unit (CPU), a floating-point accelerator (FPA), a read/write buffer (RWB), cache memory, a clock generator, buffers, and reset logic. The signal composition of the module includes: Configuration Buffer Enable (CfgEn); Page Write (PgWrt); Block Match (BlkMtch); Byte Write Mask (WrMsk); and Test Enable (TestEn). The layout of the various components on a printed circuit board (PCB) minimizes transmission line effects, such as transmission line delay (tD) and signal reflections, by keeping trace lengths as short as possible, and no line terminations are required. A heat sink (heat spreader) is provided for critical semiconductor devices, such as the CPU and the FPA. The heat sink includes a broad flat section and a button protruding from a surface thereof. An unpackaged device is mounted to the button, with a thermally and electrically conductive adhesive, and is inserted through a hole in the PCB. The broad flat section of the heat sink is mounted to one side of the PCB, and connections to the die are made with bond wires to a conductive layer on the other side of the PCB. The heat sink is advantageously employed for biasing the semiconductor device. |
