Jnc: What is a 'pended' bus?

2023-03-18T11:06:42Z

What is a 'pended' bus?

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=='pended' bus?==

What is a 'pended' bus? That it not a term I am familiar with. I see this text was cut-and-pasted from a DEC manual - which didn't define it either.

Ding a Web search for 'pended XMI' turned up only [https://www3.physnet.uni-hamburg.de/physnet/Tru64-Unix/HTML/AQTLLATE/DOCU_013.HTM this], which says that use of a 'pended bus' is "so that the bus does not stall between requests and transmissions of data" - but does not explain how it does that. Ah, searching for 'pended bus' returns [https://patents.google.com/patent/US5594875A/en Method and apparatus to provide pended transaction on a non-pended system bus], which explains that "A pended system bus is a bus which allows multiple transactions to be outstanding, or in progress, at the same time. On a pended system bus, while one CPU is trying to access an I/O device which is currently busy, other CPU and bus initiators can continue to use the system bus. The system bus, therefore, is not stalled, as it is in the case of non-pended buses .., while waiting for I/O device access. Unlike a pended bus, a non-pended bus allows only one transaction to be in progress at any given time."

"Pended" is a little-used word in English; it means 'to be put into a state where it remains undecided or unsettled' - which fits with the above. So, in the example, the first CPU's I/O device access would be 'pended', allowing the other entities to use the system bus.

This is ''a'' problem with creating articles by cut-and-pasting blocks of text (see [[Help:Contents#Goals and Content|here]] for more). Rather than do that, why not just provide a link to the text? [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 12:04, 18 March 2023 (CET)

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Jnc: What is a 'pended' bus?