DS1290,计数器移位寄存器
DS12C887,IC RTC W/RAM 128 BYTE 24-EDIP
DS12C887+,IC RTC W/RAM 128 BYTE 24-EDIP
DS12C887A,IC RTC W/RAM 128 BYTE 24-EDIP
DS12C887A+,IC RTC W/RAM 128 BYTE 24-EDIP
DS12CR887-33,实时时钟
DS12CR887-33+,IC RTC W/RAM 128 BYTE 24-EDIP
DS12CR887-5,实时时钟