Walter There is no reason a package cannot include multiple die. I see this all the time in my work. An IBIS file describes a one to one relationship between a package pin and a die pad. The old EBD description added the ability to have multiple die pads attached to a single package pin. So memory cards, etc. could be better described in an IBIS file. But in the case of multiple die inside the same "package" an IBIS file will work just fine if a package pin does not go to multiple die pads. Tom Dagostino Teraspeed Labs 9999 SW Wilshire St. Suite 102 Portland, OR 97225 USA 971-279-5325 Office 971-279-5326 FAX 503-430-1065 Cell tom@xxxxxxxxxxxxx www.teraspeed.com <http://www.teraspeed.com/> Teraspeed Consulting Group LLC 16 Stormy Brook Road Falmouth, ME 04105 401-284-1827 From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Walter Katz Sent: Friday, February 08, 2013 3:35 PM To: 'Lynne C. Green' Cc: 'IBIS-Interconnect'; 'IBIS-ATM' Subject: [ibis-macro] Re: [ibis-interconn] Re: We need to define terms System, Component, Connected, Connection, Module, .ibs Package and Die, .ibs Bare Die Lynne, I define a package as containing one die, and therefor can be described in a .ibs file. A Multi-Chip Module contains two or more die (multi means more than one!), although I think it would be perfectly OK for a EMD containing a single die. This is a semantically difference, but also has practical usage. EMD are truly post layout, while .ibs files are often used to describe pre-layout. .ibs files are often delivered by IP vendors or ASIC vendors to describe the simulation properties of a buffer or a Tx/Rx buffer pair. It is also common in a package for the IC Vendor to describe a Typ/Min/Max package interconnect subckt for all of the Models in a bus, so the difference in interconnect models for an EMD that represents a package and single die and a .ibs file is that the EMD is strictly post layout, while the .ibs file can be either post layout (subckts between the pins and die pads) or pre-layout where the subckt is defined between the pins and die pads of all the connections to a [Model]. Crosstalk in an EMD is between actual connections. Crosstalk in a .ibs model is between actual connections or between and connection and other connects in the bus, but not necessarily to specific connections. This reflects the various ways that IC Vendors are currently delivering package interconnect models. Walter From: Lynne C. Green [mailto:lgreen22@xxxxxxxxxxxxxx] Sent: Friday, February 08, 2013 5:28 PM To: Walter Katz Cc: 'IBIS-Interconnect'; 'IBIS-ATM' Subject: Re: [ibis-interconn] Re: We need to define terms System, Component, Connected, Connection, Module, .ibs Package and Die, .ibs Bare Die Thanks, Walter, Interesting. Of course, answers always create new questions... New nits: - I love Walter's statement that "connection" could include a DC blocking cap. Since that is highly clarifying, perhaps it could be added to the definition, to emphasize impedance is checked at Nyquist freq? (might need to spell out Nyquist for the newbie, but that is a different can of worms) - On second definition of "Connection", plural? - Newbie question: How is "package" different from "module". i.e. could a newbie confuse the two, or perhaps take advantage of features of one that are not in the other? (not that any IBIS model maker has ever done that before ;-) - If there is a difference, is there any "easy" way to make module and package work the same way (one vs multiple chips, multiple chips in packages, so they start looking more alike over time). Am I seeing a difference of naming, or concept, or syntax, or a real physical difference? Cheers, Lynne On 2/8/2013 12:43 PM, Walter Katz wrote: Lynne, First definition is for "Connected" fixed below. A connection may have a blocking cap. At DC it is high impedance, but will be low Impedance at Nyquist. Of course "Low" or "Small" impedance is not very precise. A long connect with a blocking cap could have in insertion loss of ~30dB at Nyquist. A bare die is mounted in a Module. The wire bond is in the Module interconnect and is accounted for in the Module interconnect module, similar for flip mounted. Walter From: ibis-interconn-bounce@xxxxxxxxxxxxx [mailto:ibis-interconn-bounce@xxxxxxxxxxxxx] On Behalf Of Lynne C. Green Sent: Friday, February 08, 2013 3:21 PM To: IBIS-Interconnect Cc: IBIS-ATM Subject: [ibis-interconn] Re: We need to define terms System, Component, Connected, Connection, Module, .ibs Package and Die, .ibs Bare Die All- My usual nits, from a "newbie" viewpoint. Where will the interconnect between bare die and package be accounted for? It is not in the IBIS [Model] or the Component [Pin] list. And apparently not in "Interconnect Subckt". Presently accounted for in [Package Model]. Quibbles on zero ohm impedance. a) bare die, where wire bond is the package. Package impedance approximately 1nH, varies with wire bond length. b) bare die, flip mounted (on module or another die). Package impedance approximately 0.1nH. Neither case is negligible at 100Gb/sec (alpha prototyping now). Having two definitions of "Connection" is confusing me. In simulation, a "node" means a dead short - one node number, negligible impedance, etc. While I can see the first definition, the second one is confusing me. Other than those nits, this is definitely clarifying things for me. Cheers, Lynne On 2/8/2013 8:00 AM, Walter Katz wrote: All, There has been two much confusion on what EMD is and a comprehensive .ibs package and on-die interconnect solutions, so I propose the following definitions to clarify future discussions. System A system consists of multiple components that have electrical connections between them. Component A basic building block of a System. A component can be a backplane, PCB, Connector, Cable, DIMM component, Multi Chip Module, Interposer, package, a packaged die, a bare die, and other things that have not been invented yet. Connected Two electrical nodes in a system are connected if the Insertion Loss between the two points at Nyquist is "Small". Connection A connections consists of a list of electrical nodes that are all connected to each other. Module A Module is a Component that has Pins that connect to other system components, and contains Components and Connections between these Components, and between these Components and the Module's Pins. EMD One proposed solution that describes Interconnect Subckts between the Module Pins and/or Module Components Pins IBIS Component Represented by a .ibs file, contains one, and only one die, [Models], package interconnect between the [Component] [Pins] and Die Pads, on-die interconnect between the die pads and the [Model]. Bare Die IBIS Component A special case IBIS Component that represents a physical Die that is mounted directly in a Module. An example of this is a multi-chip module (MCM) that contains two are more die that are mounted and wire bonded directly on the MCM surface. The [Pin] and on-die pad are at the same location, and the Package model should be treated as a zero ohm resistor. Interconnect Subckt An IBIS-ISS subckt or a Touchstone File that has ports that as described below. The ports may or may not be connected to all of the other ports. Module Pins Component Pins IBIS Package Pins Die Pads On-Die Interconnect Die Pads [Model] ports Note that a Module (and therefore EMD) never has connections to [Model]!!! Walter Walter Katz wkatz@xxxxxxxxxx Phone 303.449-2308 Mobile 303.335-6156