Data Line (TN726)
The Data Line Circuit Pack interfaces eight Asynchronous Data Units (ADUs) data devices and the TDM bus. The ADUs are typically, in turn, connected to
●A bit clock
●Bus isolation
●Eight port circuit.
Bit Clock: The bit clock circuitry is used to provide the Octal Asynchronous Terminal Mode Two EIA Asynchronous LSIs (OATMEALs) with a clock frequency that is a multiple of each baud rate. In addition, the clock rate is divided down to 160 kHz. The 160 kHz is then compared to the 160 kHz data clock of the system, and is
Bus Isolation: This portion of the circuit pack is used to isolate the microprocessor bus. Isolation is required because the realized bus load exceeds the maximum limit specified for this device, due to the large number of devices controlled by the NPE. The OATMEALs are isolated from the common bus structure.
Port Circuits. Each of the eight identical port circuits allows the connection of interface equipment having an
Throughout the circuit, various gates are used to provide a means of isolating devices for automated circuit pack testing. Typically, these devices are crystal oscillators or memory components attached to the microprocessor bus.