System for serial peripheral interface with embedded addressing circuit for providing portion of an address for peripheral devices

摘要

A microcontroller (12) provides the address bit and device data start bits for the first peripheral device (PD) in a string of PDs (20-24 or 30-34). Each PD includes a string of flipflops (72-86). If the complete address matches, then the first PD (20) shifts out the device data start bits for the next PD (22) in that string. The address bit for the next PD is provided by the pull-up or pull-down device (52) hard-wired on the SI of the next PD. The device data start bits for the next PD are provided by right-most flipflops of the previous PD. If the address bit and device data start bits match the contents of the device registers of next PD, then that next PD enables SYSCLK to shift out the contents of flipflops.