Abstract: A processor comprises memory circuitry and processing circuitry coupled to the memory circuitry. The processing circuitry is operative to retrieve from the memory circuitry an interrupt polling instruction which causes selection of an active enabled interrupt and generation of an interrupt vector for the selected active enabled interrupt. In conjunction with the selection and generation operations, an execution context of a program thread is stored in the memory circuitry, the stored execution context being utilizable to resume the program thread at an appropriate time subsequent to interruption of that thread.

Abstract: A packet, cell or other data segment received in a physical layer device from a link layer device via an interface bus is processed to determine a port address for the data segment in the physical layer device. The port address, which may be an MPHY address, is determined using a combination of a first address value obtained from a link layer address portion of the data segment and a second address value obtained from a payload portion of the data segment. The data segment is stored in a memory location identified by the port address. The memory location may comprise a particular queue of the physical layer device.

Abstract: A packet, cell or other data segment received in a physical layer device from a link layer device via an interface bus is processed to determine a port address for the data segment in the physical layer device. The port address, which may be an MPHY address, is determined using a combination of a first address value obtained from a link layer address portion of the data segment and a second address value obtained from a payload portion of the data segment. The data segment is stored in a memory location identified by the port address. The memory location may comprise a particular queue of the physical layer device.

Abstract: A virtually parallel multiplier-accumulator (VMAC) that can execute more than or less than one MAC operation in a single system clock cycle. The inventive VMAC advantageously employs a resource/time-sharing methodology with multiple sequential computational stages.

Abstract: A virtual parallel multiplier-accumulator (VMAC) that can execute more than or less than one MAC operation in a single system clock cycle. The inventive VMAC advantageously employs a resource/time-sharing methodology with multiple sequential computational stages.

Abstract: An apparatus and method that speeds the processing of data vectors in a digital processor is disclosed. In accordance with the present invention, a vector zero overhead loop with parallel issue processes multiple data elements at the same time, and yet is programmed with readable assembly language and requires neither vector registers nor a lot of extra registers to implement.

Abstract: A first register stores a value that can be used as a pointer to indirectly address a second register. The first register is referred to as a pointer register and the pointer as a register pointer. The second register may be a conventional register that stores a conventional register value (i.e., a data value or a pointer to a data value stored in external memory) or another pointer register. In certain embodiments, a pointer register can also be used to store conventional register values. Pointer registers of the present invention can be used to implement efficiently certain types of digital processing, such as circular buffers, vector processing, convolutional processing, and partitioned processing, using data in registers rather than memory.

Abstract: A method and apparatus are disclosed for powering-up a microprocessor in a system under debugger control. The microprocessor comprises I/O connection pins, internal logic, and a reset condition responsive to a reset signal. Additionally, the microprocessor has a boundary scan architecture, such as an IEEE 1149.1 (JTAG) compliant interface, which includes a boundary scan register (BSR) and at least one design-specific test data register. The BSR has normal and test modes. In the normal mode, the BSR operatively connects the internal logic to the I/O connection pins. In the test mode, the BSR operatively isolates the internal logic from the I/O connection pins. The method comprising first detecting when power is applied to the microprocessor. Once power is detected and while the microprocessor remains in the reset condition, the BSR is put into tile test mode to isolate the internal logic from the I/O connection pins.