IEEE Std. P1687.1: Translator and Protocol

Abstract

The IEEE Std. P1687.1 working group is currently exploring alternatives to IEEE Std. 1149.1 test access port (TAP) as the interface between the boundary of integrated circuits (ICs) and IEEE Std. 1687 networks. In this paper, we investigate the use of universal asynchronous receiver-transmitter (UART) to access IEEE Std. 1687 networks. We have developed a protocol to describe the information transported over UART and a hardware component to translate (retarget) information between UART and IEEE Std. 1687. The objective is to minimize the amount of information transported over UART and the area of the hardware component while maintaining the flexibility to access an arbitrary combination of instrument in the IEEE Std. 1687 network. We have developed software for the protocol translation, implemented the hardware component and IEEE Std. 1687 networks of different sizes in an field-programmable gate array (FPGA). For comparison, we developed a number of alternatives, all implemented on FPGA. The experimental results show that proposed scheme gives low overhead in terms of transported information (data) and low area of the hardware component.

Graceful Degradation of Reconfigurable Scan Networks

“…We have previously explored the impact on transporting data when including key information from PDL and ICL in a hardware component placed between a functional port, e.g., universal asynchronous receiver-transmitter (UART), and IEEE Std. 1687 [5] (see Fig. 1).…”

“…We previously explored the impact of including different amount of information in a hardware component placed between a functional port and an IEEE Std. 1687 network [5]. The most efficient solution, shown in Fig.…”

“…The software-based test scheme assumes a hardware component and protocol [5], which we extended with a mechanism to not perform capture and update when applying an iApply group if desired. The idea of the test function is to include all instruments in the active scan path, apply a test sequence, 001100 .…”

“…The software-based localization scheme has several similarities with the test function (see Section IV-B). We assume the hardware component and protocol [5] and have added a mechanism to not perform capture and update of iApply if desired. Different from testing (Section IV-B), localizations include one instrument at a time in the active scan path, apply the test sequence, 001100 .…”

Co-optimization of security and accessibility to on-chip instruments

“…The rest of the paper is organized as follows. In Section II the need of on-chip instruments is illustrated and existing ways to access these instruments are introduced [5], [6], [7], [8], [9], [10], [11]. A way to secure the test access port without embedding a private key is discussed in Section III.…”