Accession Number:

ADA224618

Title:

Technical Progress for IDDGA -OBP Upgrade. Revision

Descriptive Note:

Corporate Author:

MARTIN MARIETTA SPACE SYSTEMS INC DENVER CO

Personal Author(s):

Report Date:

1990-06-26

Pagination or Media Count:

7.0

Abstract:

The chip functionality has been defined by Martin Marietta. It was previously noted that the FA adjust control and the RND control may both be activated at the same time. When this occurs, both the Martin Marietta simulator SIMCPU and the Analytyx instruction set simulator CPUSIM produce results not consistent with the IDT device. It was determined that this mode is not useful for current OBP software. Martin Marietta recommends that the OBP Programmers Reference manual specify that the multiplier output be indeterminate when this combination of controls is applied to the device. The run closing data for the Arithmetic Logic Unit is 93090. Since this date is rapidly approaching, discussions were held regarding its design at the June TIM at Analytyx. The ALU is actually a twin ALU. Two 16 bit 49C402 ALUs are incorporated into a single device. These ALUs are independent of each other. Since the current OBP architecture does not support two complete ALUs, it is necessary to decode the microword.

Subject Categories:

  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE