As per the block diagram figure of 423,
when i activate the nSCS_C of 428 (connected to NSCS428 of 423),
the SDO428pin of 423(connected to SDO_C of 428) get multiplexed with SDO pin of 423.
ultimately microcontroller can access the 428 data via SDO pin of 423.
This is my perception got from datasheet, is it ok?