IEEE P1149.5 to 1149.1 data and protocol conversion

The proposed IEEE P1149.5 Standard Module Test and Maintenance (MTM) Bus Protocol Standard addresses hierarchical system test using a four wire (five wire with pause option) serial bus scheme. While the standard adresses many system test and maintenance issues, it is an open ended specification that allows user-defined functionality. With the broad acceptance of IEEE Std 1149.1 Boundary Scan, it is important that P1149.5 allows access to IEEE Std 1149.1 and recommends one or more possible methods of converting IEEE P1149.5 protocol and data to IEEE Std 1149.1 protocol and data. This paper proposes one technique for protocol and data conversion between IEEE P1149.5 and IEEE Std 1149.1. This proposal is under consideration with other proposals for recommendation within the IEEE P1149.5 Specification. The IEEE Proposed Std 1149.5 and IEEE Std 1149.1 are briefly reviewed from a protocol perspective to lay the groundwork for reconciliation of their differences later in the paper. A sample IEEE P1149.5 Slave interface is also developed to introduce the concept of serial to parallel conversion within the IEEE P1149.5 Slave which is necessary for error checking on 1149.1 data