Xycom XVME-113, Руководство пользователя

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XVME-113 RAM/ROM Memory Module
October 1992
3-9
3.5
PROGRAMMING PROCEDURES
This section describes the programming procedures required for the RTC. Included are procedures for initializing the
RTC, setting or reading the RTC, using the alarm function, and using the RTC as a long term timer.
3.5.1 Power-on Initialization
The RTC on the XVME-113 must be initialized after power is first applied to the device. Initialization is only required
when the power is initially turned on. As long as battery backup is enabled, the RTC will not need to be initialized after
the VMEbus system is powered up. Follow the procedure for initializing the RTC registers as indicated in the flow chart
and instructions below.
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Power Applied •When power is first applied, all registers are undefined.
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TEST bit <-- 0 • To ensure proper operation (write '0' every time).
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Wait 3 Seconds • Time delay necessary for oscillator stabilization.
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• Set the counter registers •
• and alarm registers, and
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• initialize the control •
• registers, as desired. •
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NOTE
The RTC chip has no hardware means for resetting the registers. Therefore, after
power is first applied to the device, all registers must be initialized.