摘要:
A test circuit for a VLSI integrated circuit includes interface test circuits (20) which are disposed between a logic circuit (16) an output terminal (14). The interface circuits (20) are each operable to provide a transparent interface between logic circuit (16) and output terminals (14) or force a high logic state on the output, a low logic state on the output or a floating state. A test code circuit (22) is operable to receive two logic signals from pins (24) and (26) external to the IC and determine the state of the test interface circuit (20) such that all test interface circuits (20) operate simultaneously in the same mode.
摘要:
A test circuit (10) is connected to a package pin of an integrated circuit via the first node (16). By setting the voltage on the package pin to a sufficient voltage, the test circuit becomes operable to measure DC characteristics of devices in the test circuit. The DC characteristics of the test circuit devices, such as resistors (26 and 34), diodes (44) and transistors (30 and 32) are used to estimate the AC characteristics of the actual integrated circuit. The AC characteristic estimations may be used to screen parts into various speed classes.
摘要:
An integrated circuit (42) is formed in a semiconductor layer (50) having a defined area. Functional circuitry (12) is formed in semiconductor layer (50) to occupy only a portion of the defined area of semiconductor layer (50), and thus defining an unoccupied area of semiconductor layer (50). A capacitor is formed in semiconductor layer in a substantial portion of the unoccupied area.
摘要:
A memory device (10) includes switching circuitry 22 comprising sensing and control circuits (24 and 26) to predict the next state of the output of memory device (12) and to turn on and off current sources (20) responsive to said memory output to provide faster output transitions.
摘要:
A floating point processor (10) is provided having a multiplier (48) and an ALU (54) for performing arithmetic calculations simultaneously. The output of the multiplier (48) and ALU (54) are stored in a product register (64) and a sum register (66), respectively. Multiplexers (40,42,44,46) are provided at the inputs to the multiplier (48) and the ALU (54). The multiplexers choose between data in input registers (32,34), product and sum registers (64,66), and an output register (76). Since the multiplier (48) and ALU (54) operate simultaneously, and since the outputs of the multiplier (48) and ALU (54) are available to the multiplexers (40-46), product of sums calculations and sum of products calculations may be performed rapidly. An input stage (12) uses a temporary register (18) to store data from a data bus on the first clock edge, and configuration logic (28) for directing data from the data bus and the temporary register (18) to the input registers (32,34) on a second clock edge.
摘要:
A TTL gate (26) with a Darlington output (14,14A,16) includes three circuits (28,30,32) to decrease the gate switching time during an output transition from a high to a low logic state and from a high impedance state to a low logic state. Each speedup circuit drives the gate input transistor (12) for a different length of time, ensuring that the lower output transistor (16) turns on rapidly and remains on until the output transition is complete. The circuits ensure, however, that the additional drive current (82) is time limited to avoid excessive power consumption.
摘要:
A floating point processor (10) is provided having a multiplier (48) and an ALU (54) for performing arithmetic calculations simultaneously. The output of the multiplier (48) and ALU (54) are stored in a product register (64) and a sum register (66), respectively. Multiplexers (40,42,44,46) are provided at the inputs to the multiplier (48) and the ALU (54). The multiplexers choose between data in input registers (32,34), product and sum registers (64,66), and an output register (76). Since the multiplier (48) and ALU (54) operate simultaneously, and since the outputs of the multiplier (48) and ALU (54) are available to the multiplexers (40-46), product of sums calculations and sum of products calculations may be performed rapidly. An input stage (12) uses a temporary register (18) to store data from a data bus on the first clock edge, and configuration logic (28) for directing data from the data bus and the temporary register (18) to the input registers (32,34) on a second clock edge.
摘要:
A microsequencer includes a memory array (110) which is interfaced with a push/pop register (100). Data is input to the push/pop register (100) through a multiplexer (104) and also to Read register (102). The stack comprised of the RAM (110) and the register (100) can be push or pop with control logic (120). Stack pointer (130) and Read pointer (134) are provided for storing the stack and read pointers. The Read register (102) allows reading of data independent of the contents of the push/pop register (100) and the Read pointer (134) allows independent reading of information in the RAM (110).
摘要:
A bit slice processor system includes a bit slice ALU that is cascadable to provide multiple length words. Each of the ALUs provides both command outputs and status outputs. The status outputs are interfaced with each of the package as are the command outputs. Each of the ALUs in the cascaded ALU are controlled by an instruction word to perform a predetermined processing function. Internal status information is processed to generate a command output and a status output. This command is transmitted simultaneously with the status to the remaining packages in the cascaded array to provide processing control.