摘要：许多高可靠性的系统保持了他们的快闪记忆体的备份副本应该成为一个新的软件下载任何原因而无法使用。本应用笔记介绍了DS4510 ， DS4520 ， DS4550非易失性的I / O扩展，可以用来选择适当的系统上电的闪存页。Maxim/Dallas > App Notes > GENERAL ENGINEERING TOPICS MEMORY MISCELLANEOUS CIRCUITS SWITCHES AND MULTIPLEXERS Keywords: flash, flash memory, backup, non-volatile I/O Jul 28, 2004 APPLICATION NOTE 3291 Using DS4510/DS4520/DS4550 to Select Backup Flash Memory Many high-reliability systems maintain a backup copy of their flash memory should a new software download become unusable for any reason. This application note describes how the DS4510, DS4520, and DS4550 non- volatile I/O expanders can be used to select the proper page of flash memory on system power-up. The DS4510, DS4520, and DS4550 are a series of nonvolatile I/O expanders. Since they retain their programmed output values when the system is powered down, they can be used to se……