Abstract: An integrated circuit including a processor, a processor bus coupled to the processor, a system bus and a trace buffer. The trace buffer may capture activity on either the processor bus or the system bus.

Abstract: A integrated circuit includes a processor, a bus coupled to the processor, a memory interface and an interface bus. The memory interface provides an interface between the bus and at least two memory devices including a first memory device and a second memory device. The interface bus is coupled to the first memory device, the second memory device and the memory interface. Control signals, address signals and data signals are transmitted over the interface bus.

Abstract: A method and apparatus for determining a width of an external memory is described. The method comprises reading a data from memory, and if the data matches an expected data key, determining the width of the memory.

Abstract: A method of communicating with a configurable system-on-chip via a test interface is described. First, an interface is coupled to a configurable system-on-chip and a first command is sent to the interface from a tester. The next command execution is then blocked. Next, the first command is executed in the configurable system-on-chip. Data is then output from the configurable system-on-chip and written to a register in the interface. The data output includes a ready bit. Next, the data from the register is read. The first bit read is an asserted ready bit. The next command execution is then enabled. When the asserted ready bit is received in the tester, the tester sends a second command to the interface. The second command is then executed in the configurable system-on-a-chip.

Abstract: An integrated circuit includes a debugging unit which uses a multi-master general purpose bus within the IC to perform debugging functions. The storage elements of the IC are mapped into the address space of the general purpose bus. The debugging unit can operate as a bus master and read from or write to the storage elements of the integrated circuit directly with the general purpose bus. Thus, the integrated circuit can be rapidly configured for testing and debugging. Furthermore, the debugging unit can work with a breakpoint unit on the IC to detect and analyze specific situations on the IC.

Abstract: A bidirectional bus structure includes a first multiplexer path propagating signals in a first direction and a second multiplexer path propagating signals in a second direction. For one embodiment, the bus structure further includes a circuit for selectively combining the signals on the first and second paths and selectively propagating the signal on one of the first and second paths. For another embodiment, the bus structure further includes a logic gate for combining the signals on the first and second paths and a circuit for selectively propagating the signal on one of the first path, the second path, and an output signal of the logic gate. For both embodiments, the present invention allows multiple signals to use the bus without contention, thereby providing an extremely flexible interconnect routing resource. This bidirectional bus can selectively drive signals onto the general interconnect as well as onto a system bus in a configurable system on a chip.

Abstract: A method for asserting an address alignment of an address for a memory-mapped device in a logic design is disclosed. An align primitive comprising an alignment size port, an input address port and an output address port is used. The alignment size port has data indicating a desired address boundary. The input address port is used for an address to be verified against the desired address boundary. The output address port is used to provide an address that is on the desired address boundary. The address to be verified against the desired address boundary is provided at the output address port when that address meets the desired address boundary. Another method for specifying an offset address for a memory-mapped device in a logic design is disclosed. An offset primitive is used to assert an address for the memory-mapped device. The offset primitive comprises an incoming address port, an outgoing address port and an offset value port. The offset value port has a data value indicating a desired address offset.

Abstract: The I/O circuit of the present invention provides optimal flexibility and performance using a number of different structures and methods. The present invention provides a signal follower circuit for an input pad. In one embodiment, the output buffer is capable of injecting a constant onto a pad during reconfiguration of a configurable system logic circuit. The present invention also provides a circuit for generating a programmable data propagation delay, thereby guaranteeing zero hold time for an arbitrary input register. Zero hold time is accomplished by allowing the user to optimally characterize clock delay to a given input/output circuit. The present invention also provides fast switching between input pads, thereby minimizing data propagation delay between the input pads. Additionally, the present invention reduces time spent in production product test by facilitating the testing of multiple routes with one test configuration.

Abstract: A programmable input/output memory architecture. The programmable input/output memory cells are disposed in two segments about the periphery of the chip. Each segment has two data buses for separate reading and writing of the configuration register. Each cell is selected and configured according to user specifications. Corresponding memory cells from each segment share the same select line, therefore two bytes of configuration data are accessed together and the data is propagated through both segments approximately concurrently thereby reducing propagation delay.

Abstract: The configurable processor system includes a processor, an internal system bus, and a programmable logic all interconnected via the internal system bus, on a single integrated circuit.

Abstract: A method and system for the rapid and precise configuration of a bank of logic in a configurable system on a chip. The configuration memory array is partitioned into a plurality banks. Configuration circuitry is implemented for each bank. This allows for the configuration of one or more banks while the other banks remain operable.

Abstract: A method and apparatus for a power-on reset system is provided. The power-on reset system comprises a voltage sense circuit for determining whether a voltage level is above a threshold and a write/rewrite verifier circuit for determining whether the voltage level is high enough to write to and rewrite a memory cell content. A power-on reset pulse emitted by the power-on reset system if the voltage level is above the threshold and high enough to write to and rewrite the memory cell. For one embodiment, this is system generates an initial POR pulse upon power-up but can thereafter be selectively disabled and consume zero power.

Abstract: An output driver to reduce totem pole current is provided. The output driver comprises a first delay element outputting a delayed first driver signal, and a first selection unit receiving as an input the first driver signal and the delayed first driver signal. The output driver further comprises a second delay element outputting a delayed second driver signal and a second selection unit receiving as an input the second driver signal and the delayed second driver signal. A selection signal for the first selector is the first driver signal, and the selection signal for the second selector is an inverted first driver signal, such that a path that is not presently driving is switched off first, prior to the opposing driver being turned on.