When the calling instruction is executed, it will protect the return entry address, that is, the location of the instruction, 2348H, stored after LCALL 3456H of 2345H. The lower 8 bits are put on the stack first. SP automatically adds 2. The instruction PC of CPU points to 3456H.

At this time: SP=72. PC=3456H .(SP，72)=23H，(SP- 1，7 1)=48H .