Abstract:
A cable length estimation circuit (110) for receiving an input MLT-3 signal provided through an arbitrary length cable (104) and providing a control signal to an equalizer (108) indicating the estimated length of the cable enabling the equalizer (108) to compensate for distortion of the MLT-3 signal resulting from the cable. The cable length estimation circuit (110) includes an edge rate detection circuit (400) for measuring the rate of change in voltage with respect to time during transitions of the MLT-3 signal to provide an indication of cable length. The cable length estimation circuit (110) can also include a digital averaging circuit (402) which provides an average value for signals from the edge rate detection circuit for a desired number of transitions of the MLT-3 signal. The cable length estimation (110) can also include a baseline wander detection circuit (404) which functions so that previous cable length estimations are provided when baseline wander is detected.
Abstract:
A mu BGA carrier for packing and shipping of a plurality of mu BGA packages is specially adapted for facilitating the inspection of the solder balls on the bottom surfaces of the mu BGA packages. The carrier consists of a tray member (12) having a plurality of first pockets (28) disposed therein for packing and storing the plurality of mu BGA packages, and a lid member (14) having a plurality of second pockets (40) formed therein. The second pockets are vertically aligned with corresponding ones of the plurality of first pockets in the tray member when the lid member is placed on top of the tray member. The carrier can be flipped upside-down so that when the tray member is removed the solder balls are facing upwardly to allow inspection of the same.
Abstract:
A method and apparatus wherein the height over the complete surface of interest on a wafer/material is scanned and mapped, using either a central or non-central focus system. The type of data gathered is similar to that which is normally acquired in operation of the particular focusing system indicative of the wafer/material surface height. The difference is that, according to the present invention, a much larger number of data points are sampled and then processed to provide improved focus information. These data are stored and used to calculate corrections in both the vertical position/height and tilt of the material/wafer for each exposure field, such as the areas (34) in Fig. 5b and 6b. The invention sorts out selected height data indicating periodic variations in surface height. Such data are normally not indicative of true wafer surface height variations, but instead are the result of periodic variations in wafer material composition caused by underlying structure relating to the particular circuitry. These periodic variations are distinguished from non-periodic variations, and are subtracted out of the total height measurement data to yield corrected surface height data. The present invention uses the corrected surface height data to calculate an optimum focus height for a given exposure area such as area (34).
Abstract:
A flash memory device is divided into two or more banks. Each bank includes a number of sectors. Each sector includes flash memory cells. Each bank has a decoder that selectively receives an address from an input address buffer or from an internal address sequencer controlled by an internal state machine. The output data for each bank can be communicated to a read sense amplifier or a verify sense amplifier. The read sense amplifier connects to the output buffer while the verify sense amplifier connects to the state machine. When one bank receives a write command, the internal state machine takes control and starts the program or erase operation. While one bank is busy with a program or erase operation, the other bank can be accessed for a read operation.
Abstract:
A system and method for performing software patches for embedded system devices in which the firmware of the system is included in non-alterable storage of the device. The patch mechanism provides a means for finding firmware errors, prototyping fixes to the errors and/or prototyping new functionality of the firmware of the embbeded system. The system comprises an embedded system device coupled to an external memory. The device includes a non-alterable memory, including firmware, coupled to a processor. The device further includes a relatively small amount of patch RAM within the device also coupled to the processor. The patches are loaded from the external memory into the patch RAM. The device further includes a means for determining if one or more patches are to be applied. If the device detects a patch to be applied, the system loads the patch from the external memory into the patch RAM. The device also includes a breakpoint register. When the value of the program counter of the processor equals the value in the breakpoint register, a patch insertion occurs, i.e., the processor deviates from executing firmware to executing patch instructions. Preferably, the embedded system device comprises a single integrated circuit. The processor may include a plurality of breakpoint registers. The patch may be encrypted for increased security. Multiple patches may be chained together, and run-time patch replacement is contemplated.
Abstract:
A method of inspecting a lens (16) includes projecting a first amount of radiation through a first test pattern (42, 44) and the lens to provide a first lens error associated with a first heating of the lens, projecting a second amount of radiation through a second test pattern (52, 54) and the lens to provide a second lens error associated with a second heating of the lens, and using the first and second lens errors to provide image displacement data that varies as a function of heating the lens. In this manner, corrections can be made for localized lens heating that is unique to a given reticle. The method is well-suited for photolithographic systems such as step and repeat systems.
Abstract:
A digital loop filter in the carrier-recovery loop of a digital communications receiver. The recovery loop is a PLL that keeps the receiver oscillator locked to the carrier wave, and the loop filter provides control over the PLL's frequency response by conditioning an error signal that is fed back to the receiver oscillator. In the present invention, the error signal is a digital signal, and the loop filter is implemented in digital hardward. With this implementation the characteristics of the loop filter are determined by logic design rather than by physical features of analog components, thereby giving this filter a more precise function than one with analog integrators. This implementation is also immune to the low tolerances typical of the manufacturing process for analog devices (especially on monolithic circuits), and is more easily adjusted than its analog counterparts. Two gain coefficients characterize the loop filter in the present invention. These gain coefficients are chosen to be powers of two, simplifying the process of multiplying them with the digital error signal. The gain coefficients are read from a memory, making the loop filter easily programmable. By changing the gain coefficients during operation of the receiver, the carrier-recovery loop can be placed in one of the several operating modes, including acquisition, tracking, and hold. The receiver can be configured with the appropriate values of the gain coefficients for each operating mode during the initial assembly and during subsequent reconfigurations.
Abstract:
An arrangement for monitoring clock frequency variations on a peripheral bus (211) is provided to improve operations of the peripheral device (118, 119) despite changes in the clock frequency. In one aspect of the arrangement, a processing unit (101) is coupled to a host bus (103) which in turn is coupled to a peripheral bus which is coupled to a peripheral device. A monitoring arrangement (121) is provided which detects a change in the clock frequency of the peripheral bus and determines if the frequency change exceeds a threshold associated with the peripheral device. If the threshold is exceeded, the peripheral device is informed that the clock frequency of the peripheral bus has changed. A peripheral device operating at different operating levels may use the information from the monitoring arrangement to alter the operating level of the peripheral device to conform to the new bus clock frequency.
Abstract:
A memory array test and characterization capability is disclosed which allows DC characterization of the memory cells, the bit lines, and the sense amplifiers. A row decoder is provided which includes a static wordline select signal to disable self-resetting logic within the row decoder and allow the word line to remain active for a user-controlled length of time. An analog wordline drive capability allows the active wordline to be driven to a user-controllable analog level. Direct access to a pair of bitlines is provided by a multiplexer which is statically decoded to couple a pair of isolated terminals to the respective bitlines within the decoded column. This allows DC voltage levels to be impressed upon each of the two bitlines within the decoded column and/or the two bitline currents to be sensed. A separate power connection is provided for the memory array which allows operating the memory array at a different power supply voltage than the remainder of the circuit. By utilizing one or more of these features together, several tests of the memory array may be performed, including characterizing the DC transfer function of the memory cells, the standby power of the memory array, the static noise margin of the memory cells, the alpha particle susceptibility of the memory cells as a function of memory cell supply voltage, the offset voltage of bitline sense amplifiers, and others.
Abstract:
A highly suitable power conservation technique involves extending multiple word lines over a memory array row and connecting a portion of the memory cells of the memory array row to each of the word lines. Power is supplied only to the portion of the memory cells that is accessed, eliminating the static power consumption of the non-accessed memory cells. By connecting multiple word lines to select a portion of a memory row, a column address of the memory is mapped into a row decode space. Multiple metal layers in a complex integrated circuit may be exploited to form cache block select lines using multiple word lines per cell row. A storage includes a plurality of storage cells arranged in an array of rows and columns, a plurality of bit lines connecting the array of storage cells into columns, and a plurality of word lines connecting the array of storage cells into rows. The plurality of word lines include multiple word lines for a single row of the plurality of rows so that multiple portions of the storage cells in the single row are addressed by corresponding multiple word lines.