摘要:
A programmable logic array (PLA) is comprised of double-personalized cells conventionally arranged in an AND and OR array. In order to activate redundant or Don't Care positions, i.e., array positions not being used for performing the respective PLA functions, control circuits are provided preceding the AND array as well as between the AND and the OR array. This allows an increase in the number of possible PLA functions to be performed by a given PLA thus providing PLA's with improved functional density. The control circuits essentially consist of two-stage AND-OR circuits being fully compatible with the AND and OR array technology of the PLA. For optimum utilization of the Don't Care positions and planes, each functional input can be switched to any discretionary functional line of the PLA. By providing an additional control line in the OR array, the control logic for the entire OR array is reduced to only two AND gates.
摘要:
An apparatus and a method to automatically locate defects and to automatically insert and personalize dummy lines in a PLA having latches controlling the cross points of the AND and OR array. Upon occurrence of an error in the PLA, a check signal is generated which interrupts normal operation of the PLA and which initiates a test procedure. The cross point latches are automatically loaded with test patterns and the output of the PLA is analyzed to locate the defective part, for example, a damaged cross point transistor, short circuited or open line. The dummy lines are repersonalized automatically to replace lines which are defective themselves or which are connected to defective crosspoints.
摘要:
The invention relates to a device and a process for the control of a data transmission channel or data bus, in particular a data bus on which the data is transmitted in a bit serial fashion according to a prescribed transmission protocol or bus protocol. The multitude of data buses which currently exist or will be developed in the future have their own proprietary data bus protocols and this means that for almost every data bus a special control device is required. The invention just described permits a multitude of data buses to be controlled by using a hierarchical processor architecture with at least two processor levels, which are respectively optimized for specific control tasks. The invention can be used for the control of a multitude of data buses, on which data is transmitted according to different transmission protocols. The invention is particularly suitable for the control of a multitude of field data buses or field buses for general applications, and in particular for the control of field buses in motor vehicles, such as ABUS, CAN bus, SAE bus J1850 or VAN bus.
摘要:
A computer system having an optimized display controller is disclosed. The computer system has a central processing unit connected to a system bus. Within the computer system, both a system memory and a video memory are connected in parallel to the system bus. In addition, the computer system also includes a display controller that is connected only between the system bus and a video display.
摘要:
Each of the check bits of an ECC codeword is generated in parallel in a byte serial sequence to permit structuring of the ECC device so that it has general application. For this purpose a byte wide check bit generator is provided for each of the check bits. These check bit generators contain generalized gating logic controlled by stored data that is capable of passing any combination of the bits making up the byte. As each byte enters such a check bit generator, the data controlling the gating logic is changed to generate a partial sum of the check bit using only those data bits from that data byte designated by the H matrix on the ECC. The partial check bits are then accumulated modulo 2 to generate the check bit to be stored with the data bits.