Abstract: A performance monitor system includes a core processor (115), a core processor associated device, such as a cache (123), and first logic, such as performance logic (127). The core processor (115) is operable to execute information. The core processor associated device provides a first signal (CACHE_PERF), which defines performance of the core processor associated device (123) during operation of the core processor (115). The first logic (127) is coupled to the core processor associated device (123) and monitors the first signal (CACHE_PERF) in response to a second signal (WPT0,1), which defines a match of user-settable attributes associated with the operation of the core processor (115).

Abstract: A data processing system (10) has a multifield register (62) which has two fields, a selection field (90) and an information field (91). The selection field (90) identifies the source of the information loaded in the information field (91). In one embodiment, the multifield register (62) is an interrupt flag register (62) and the selection field (90) identifies which of the two registers portions (59,60) of the interrupt pending register (58) is loaded into the multifield register (62). The low register portion (59) can identify up to thirty-one sources of interrupt requests and the high register portion (60) can identify up to thirty-two sources of interrupt requests even though the information field (91) is only thirty-one bits. This is achievable because the selection field (90) may serves a dual function, namely as a flag bit and as bit-32 of the interrupt pending register (58).

Abstract: A sense amplifier (10) has a pair of cross-coupled latches (12, 14, 16, 18) connected between a first voltage supply (V.sub.DD) and the sources of two transistors (20, 22). The gates of the two transistors receive a voltage differential to be sensed. The drains of the two transistors are coupled to a second voltage supply (V.sub.SS) through an enabling transistor (24). The resulting sense amplifier is fast, small, and relatively simple to construct.

Abstract: A memory (20) includes a nonvolatile memory array (32) and a volatile memory array (22). The nonvolatile memory array (32) is subdivided into banks of memory cells. The volatile memory array (22) may also be subdivided into multiple banks, and is smaller than the nonvolatile memory array (32). A transfer circuit (40) transfers the contents of a bank of nonvolatile memory array (32) into a bank of volatile memory array (22) before the data can be accessed by a processor (160). In addition, a preload decision logic circuit (180) may transfer a bank of nonvolatile memory array (32) into volatile memory array (22) invisibly to the processor (160), to have the data available when needed, thus avoiding a space fault. Coupling a smaller volatile memory array (22) to a nonvolatile memory array (32) combines the advantages of faster access times and nonvolatility without greatly increasing the size of the memory (20).

Abstract: An ATD memory has an input buffer which latches addresses while maintaining good D.C. margin, hysteresis, and transition detection. The input buffer includes two input circuits for receiving the address. A transmission-gate type latch is used to latch the outputs of the two input circuits. An internal buffer circuit receives the output of the latch and provides internal address signals useful to a decoder in selecting a memory cell. The internal buffer circuit also provides slow and fast signals useful in performing transition detection. The latch either provides outputs responsive to the address signal or an output representative of the address signal at the time a latch enable signal is received.

Abstract: A cache TAG, which has a compare mode, an and/or/invert mode, and a read mode, has a programmable comparator which receives an external data signal and an output from an array of memory cells and provides an output to a secondary amplifier. The secondary amplifier provides an output to a match comparator in the compare mode and the and/or/invert mode and to an output buffer in the read mode. The programmable comparator is programmable according to the mode of the cache TAG. The compartor uses selectively enabled transmission gates which provide minimal delay in providing the appropriate data to the secondary sense amplifiers.