-------------BEGINNING OF IR---------------- VHDL Issue Number: 2044 Language_Version: VHDL-2002 Classification: LRM Examples, Notes and Appendices Summary: Deprecation of linkage ports affects boundary scan description language Relevant_LRM_Sections: Annex E: Features under consideration for removal Related_Issues: Key_Words_and_Phrases: linkage ports, deprecated features, BSDL Authors_Name: Peter Ashenden Authors_Phone_Number: +61 8 8339 7532 Authors_Fax_Number: +61 8 8339 2616 Authors_Email_Address: peter@ashenden.com.au Authors_Affiliation: Ashenden Designs Authors_Address1: PO Box 640 Authors_Address2: Stirling, SA 5152 Authors_Address3: Australia Current Status: VASG-Approved Superseded By: ------------------------ Date Submitted: 11 October 2004 Date Analyzed: 28 October 2004 Author of Analysis: Chuck Swart Revision Number: 3 Date Last Revised: 10 May 2005 Description of Problem ---------------------- Annex E lists the linkage ports feature as under consideration for removal and recommends against using the feature. IEEE Std 1149.1 defines the Boundary Scan Description Language (BSDL) that is widely used in test applications. BSDL uses a subset of VHDL to describe the pin connections to a device under test. The subset includes use of linkage ports for power supply, ground and not-connected pins. Should linkage ports be removed from VHDL, BSDL specifications would no longer be valid VHDL descriptions. Proposed Resolution ------------------- Do not remove linkage ports from the language. Remove the feature from the list in Annex E and remove the notes in 1.1.1.2 and 4.3.2. Add a note or note in relevant places cross referencing 1149.1. VASG-ISAC Analysis & Rationale ------------------------------ The author's description of the problem is correct and the proposed solution should be adopted. VASG-ISAC Recommendation for IEEE Std 1076-2002 ----------------------------------------------- No change is needed. VASG-ISAC Recommendation for Future Revisions --------------------------------------------- Linkage ports should not be removed from the language. Remove the feature from the list in Annex E and remove the notes in 1.1.1.2 and 4.3.2. In addition, notes should be added in relevant places indicating that linkage ports are used in 1149.1. -------------END OF IR----------------