https://gunkies.org/index.php?action=history&feed=atom&title=KW11-P_Programmable_Real-Time_Clock 2026-05-01T09:06:01Z Revision history for this page on the wiki MediaWiki 1.30.1 https://gunkies.org/w/index.php?title=KW11-P_Programmable_Real-Time_Clock&diff=25207&oldid=prev 2022-02-10T12:22:41Z

<p>Fairly complete</p> <p><b>New page</b></p><div>&lt;!-- [[Image:M787-KW11-P.jpg|300px|thumb|right|KW11-P card]]<br /> --&gt;<br /> The '''KW11-P Programmable Real-Time Clock''' is a [[UNIBUS]] [[peripheral|device]] option which can either provide interval counting, or produce either single or repeated [[interrupt]]s at a programmed rate (at a multiple of the base rate). Four different base clock rates are available:<br /> <br /> * 100 KHz<br /> * 10 KHz<br /> * line rate from the [[alternating current|AC]] power provided to the [[power supply]]<br /> * external<br /> <br /> The programming interface is fairly simple; there are three [[register]]s:<br /> <br /> * control/status<br /> * count set<br /> * counter<br /> <br /> The counter register can be set to count up or down, governed by the selected rate; an interrupt can be triggered when it reaches 0 (on overflow or underflow). It can then optionally be automatically reloaded from the count set register.<br /> <br /> ==Implementation==<br /> <br /> Physically, the KW11-P is an [[DEC card form factor|quad]]-height board ('''M7228'''), which plugs into a [[Small Peripheral Controller|SPC]] slot in a [[backplane]].<br /> <br /> ==Control and Status Register (CSR)==<br /> {{16bit-header}}<br /> | ERR || colspan=7 | Unused || DONE || INTENB || FIX || UP/DN || MODE || colspan=2 | RATE || RUN<br /> {{16bitoctal-bitout}}<br /> <br /> *ERR - Overflow/underflow before previous interrupt completed<br /> *DONE - Set on overflow/underflow (causes an interrupt when that happens, if the INTENB bit is set)<br /> *INTENB - Interrupt enable<br /> *FIX - Diagnostic count<br /> *MODE - Count up/down<br /> *MODE - Single/repeat interrupt<br /> *RATE<br /> **00 - 100 KHz<br /> **01 - 10 KHz<br /> **10 - line<br /> **11 - external<br /> <br /> All [[bit]]s are read/write, except FIX (write-only), and DONE and ERR (read-only).<br /> <br /> ==External links==<br /> <br /> * [http://www.bitsavers.org/pdf/dec/unibus/DEC-11-HPWB-D_KW11P_Oct72.pdf KW11-P programmable real-time clock manual] (DEC-11-HPWB-D)<br /> * [http://www.bitsavers.org/pdf/dec/unibus/KW11-P_Schem_Aug73.pdf KW11-P programmable real-time clock engineering drawings]<br /> <br /> [[Category: UNIBUS Peripherals]]</div>

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