摘要:
An apparatus for initiating partial transactions in a peripheral interface circuit for an I/O node of a computer system. An apparatus for performing partial transfers on a peripheral bus in response to a request for a stream of data includes a data buffer coupled to a control unit. The data buffer may be configured to store one or more data packets each containing data forming a portion of the data stream. The control unit may be configured to determine the presence of data packets stored in the data buffer that collectively contain a sequence of data forming a portion of the data stream. The control unit may be further configured to cause the sequence of data to be conveyed on the peripheral bus.
摘要:
Timing delays in a double data rate (DDR) dynamic random access memory (DRAM) controller (114, 116) are trained. A left edge of passing receive enable delay values is determined (530). A final value of a receive data strobe delay value and a final value of a transmit data delay value are trained (540). A right edge of passing receive enable delay values is determined using a working value of the receive data strobe delay (550); and a final receive enable delay value intermediate between the left edge of passing receive enable delay values and the right edge of passing receive enable delay values is set (560).
摘要:
A system and method for memory incoherent verification of functionality of an HDL (Hardware Description Language) design of a computer system component is disclosed. A simulated model of the HDL design receives a memory read stimulus from a stimulus file through a simulated first bus. The simulated model of the HDL design is configured to send its response to the stimulus onto a simulated second bus. A transaction checker receives the response from the simulated second bus and analyzes it to verify operation of the HDL design of the computer system component. The stimulus file and the transaction checker are both stored in the computer system memory. The simulated model's response to the memory read stimulus is evaluated by the transaction checker independently of any previous memory write stimulus from the stimulus file. There is no need to have a previous memory write operation or a master initialization of the system memory for every memory read operation. This enhances the sequences of operations that may be applied to a device under test. Multiple simulated models may read or write into the memory without timing constraints.
摘要:
A verification system and method for verifying operation of an HDL (Hardware Description Language) design of a computer system component are disclosed. The computer system is configured to interface between a first bus and second bus. During verification, a simulated model of the HDL design is coupled to a simulated first bus and a simulated second bus. A designated stimulus is applied to the simulated model through the simulated first bus. A stimulus file stored in the computer system memory is configured to specify the designated stimulus to be applied. In response to the designated stimulus, the simulated model initiates bus cycles on the simulated second bus. A transaction checker is provided in the computer system memory to receive information relating to these bus cycles from said simulated second bus. By employing two different busses--one to apply a stimulus and the other to resolve the bus cycle through transaction checking--an effective decoupling of test stimulus from the checking environment is achieved. Due to decoupling, the test environment can be made more robust, and can be used to generate random responses, remap memory, inject errors into data streams etc.
摘要:
An apparatus for providing packets in a peripheral interface circuit of an I/O node of a computer system. The apparatus includes a buffer that may be configured to accumulate data received on a first bus. The apparatus further includes a control unit coupled to the buffer which may be configured to transmit a data packet containing a first number of bytes of the data in response to detecting that any of the bytes of the data is invalid. The control unit may be further configured to transmit the data packet containing a second number of bytes of the data in response to detecting that all of the bytes are valid.
摘要:
A buffer circuit for rotating outstanding transactions. A buffer circuit includes a buffer and a command update circuit. The buffer may be configured to store packet commands that belong to a respective virtual channel of a plurality of virtual channels. The packets may be stored in the buffer to await transmission upon a peripheral bus. Once a given packet is selected for transmission, a peripheral bus cycle corresponding to the given packet command may be generated upon the peripheral bus. The command update circuit may be configured to generate a modified packet command in response to receiving a partial completion indication associated with the peripheral bus cycle. The command update circuit may also be configured to cause the modified packet command to be stored within the buffer.
摘要:
A peripheral interface circuit for handling graphics responses in an I/O node of a computer system. A peripheral interface circuit includes a buffer circuit coupled to receive packet commands. The buffer circuit includes a plurality of buffers each corresponding to a respective virtual channel of a plurality of virtual channels for storing selected packet commands that belong to the respective virtual channel. The peripheral interface circuit may determine whether a given one of the received packet commands is a graphics response belonging to a particular respective virtual channel. In response to determining that the given packet command is a graphics response belonging to the particular respective virtual channel, the buffer circuit may cause the given packet command to bypass the plurality of buffers.
摘要:
Timing delays in a double data rate (DDR) dynamic random access memory (DRAM) controller (114, 116) are trained. A left edge of passing receive enable delay values is determined (530). A final value of a receive data strobe delay value and a final value of a transmit data delay value are trained (540). A right edge of passing receive enable delay values is determined using a working value of the receive data strobe delay (550); and a final receive enable delay value intermediate between the left edge of passing receive enable delay values and the right edge of passing receive enable delay values is set (560).
摘要:
A method and apparatus for reducing latency in a peripheral interface circuit of an I/O node of a computer system. The apparatus includes a buffer coupled to a control unit. The buffer may be configured to receive data on a first bus and the control unit may be configured to generate a first command type in response to receiving a first quantity of data having invalid bytes within the buffer. The control unit may be further configured to generate a second command type in response to a receiving within the buffer a second quantity of data having no invalid bytes. Further, in response to receiving a particular transaction type, the control unit may be configured to generate the second command type before the first quantity of data is received within the buffer.
摘要:
A buffer circuit for a peripheral interface circuit in an I/O node of a computer system. A buffer circuit includes a first buffer and a second buffer. The first buffer may be configured to store a plurality of selected packet commands within a plurality of storage locations. The second buffer is coupled to the first buffer and may be configured to store a plurality of index values. Each index value corresponds to one of the storage locations in the first buffer. The buffer circuit further includes a write logic circuit that is coupled between the first buffer and the second buffer. The write logic circuit may be configured to successively read each of the plurality of index values from the second buffer and to cause a selected packet command to be stored in each storage location corresponding to each of the plurality of index values within the first buffer.