Computer interface adapter for supporting data communication between a parallel signal device and a serial signal device

Abstract

A computer interface adapter is provided to support data communication been a parallel signal device operating at the MIL-STD-1397B Type B interface and a serial signal device operating at the MIL-STD-1397B Type E interface. A first converter, connected to the input and output channels of the parallel signal device, converts parallel format data between the Type B voltage level and a standard transistor-transistor-logic (TTL) level. A second converter, connected to the input and output ports of the serial signal device, converts serial format data between the Type E voltage level and the standard TTL level. Staging memory is provided to temporarily store parallel format data at the standard TTL level. A parallel-to-serial converter converts parallel format data in the staging memory into serial format data at the standard TTL level and passes same to the second converter. A serial-to-parallel converter converts serial format data passed from the second converter into parallel format data at the standard TTL level and passes same to the staging memory. Combinational logic circuitry, in communication with the first converter, the parallel-to-serial converter and the serial-to-parallel converter, processes handshake protocol at the standard TTL level between the parallel signal device and the serial signal device. In addition, the logic circuitry latches parallel format data through the staging memory in accordance with the handshake protocol.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A computer interface adapter for transferring data between a parallel signal device operating at a first digital voltage level and a serial signal device operating at a second digital voltage level, comprising: first means for converting data between said first digital logic level and a third digital logic level;   second means for converting data between said second digital voltage level and said third digital logic level;   third means for storing data at said third digital logic level in a parallel format;   fourth means for converting between said data stored in parallel format and serial data at said third digital logic level; and   combinational logic means for controlling data transfers between said first means, said second means, said third means and said fourth means.   
     
     
       2. A computer interface adapter as in claim 1 wherein said parallel signal device operates at the Military Standard MIL-STD-1397B Type B digital voltage level, and wherein said serial signal device operates at the MIL-STD-1397B Type E digital voltage level, said third means comprising 32-bit register means. 
     
     
       3. A computer interface adapter as in claim 1 wherein said third digital logic level is a standard transistor-transistor-logic (TTL) level.