Abstract: A high bit-rate serial communications link encodes data by inserting non-data 0's and 1's. These extra bits are removed by a decoder at the receiving end of the link. Transmission of data can be made along optical fibers.

Abstract: A barrel shifter for a floating point processing unit can be optimized by having an automatic normalization feature. A multi-stage shifting unit is employed with external circuitry to verify that only leading zeros would be shifted out before activating a given shifting stage. Bit reversers are also used on the input and the output side of the barrel shifter in order to minimize the size and complexity of the circuit while still allowing bi-directional shifting.

Abstract: A memory apparatus including an array of storage elements connected to a plurality of addressing lines for selectively connecting a group of the storage elements to a plurality of data lines. Protection circuitry is provided that is connected to the address lines for storing flags corresponding to selected groups of the storage elements to be protected. Write circuitry is provided that is connected to the address lines and to the array of storage elements for preventing the writing into the storage elements addressed by the address lines when the address is within the address of the protected groups. Control circuitry is provided that is connected to the protect circuit and the write circuit for controlling the input of the protect group addresses and for enabling the write circuit means during a write operation. The memory apparatus further includes the capability to provide protection from writing from a direct memory access source or from a central processing unit source.

Abstract: A memory apparatus including an array of storage elements connected to a plurality of addressing lines for selectively connecting a group of storage elements to a plurality of data lines. Control circuitry is also provided that is connected to the array for regulating the reading and writing of data to and from the data lines to the storage elements addressed by the address lines. A pipeline circuit is also provided that is connected to the address lines and to array of storage elements to store in response to the control circuit an address contained on the address lines. This memory system architecture allows for the address to be stored to allow the second address to be placed on the address lines while the first addressed data is being accessed from the memory array. This memory system also provides for the parity to be generated for the data in the array during the access of the data for the first address or after the pipeline circuit has been loaded with the second address.

Abstract: A memory apparatus including an array of storage elements connected to several addressing lines for selectively connecting a group of the storage elements to multiple data lines. The memory apparatus further includes a parity circuit connected to the data lines and storage elements for selectively generating parity to designate the validity of the selected group of data connected in the portion of storage elements selected by the address lines and storing the parity in the array with the data. Control circuitry is further included for controlling the generation of parity by the parity circuit. The parity generation in this memory system is programmable according to control lines that are connected to the control circuit. The parity circuit may generate the parity output either in the same cycle as the memory access or in the next succeeding cycle of memory access. The output buffer for the parity signal may also be programmable in either a push-pull or a pull-down only configuration.

Abstract: A high bit-rate serial communications link encodes data by inserting non-data 0's and 1's. These extra bits are removed by a decoder at the receiving end of the link. Transmission of data can be made along optical fibers.