Datasheet
PCF2129 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 7 — 19 December 2014 53 of 86
NXP Semiconductors
PCF2129
Accurate RTC with integrated quartz crystal for industrial applications
In this example, the Seconds register is set to 45 seconds and the Minutes register to 10 minutes.
Fig 31. SPI-bus write example
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In this example, the registers Months and Years are read. The pins SDI and SDO are not connected together. For this
configuration, it is important that pin SDI is never left floating. It must always be driven either HIGH or LOW. If pin SDI is left
open, high I
DD
currents may result.
Fig 32. SPI-bus read example
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