In addition you may need a acknowledge from slave for accepting a data bit sent on clock interrupt especially when slave uC is in other interrupts. The same acknowlege signal master can use if it is receiving data from slave for each bit.


So it can be done like this:

MasteruC int0 to slave1uC into (clock1)
MasteruC pinX to Slave1uC pinx (Data1)
MasteruC piny to Slave1uC piny (Acknowledge1)

MasteruC int1 to Slave2uC int0 (clock2)
MasteruC pinx to Slave2Uc pinx (Data2)
MasteruC piny to Slave1uC piny (Acknowledge2)


Basically the all three signals are shared between Master and slave. I think it is necessary to acknowledge each bit send either from master to slave or vice versa when other interrupts can not be disabled.

V.Nagarajan.