This can be done.After sending signature byte read signal the data will be on port1 of 89c2051 and I will make master mcu to loop here so that I can measure the data.Using uart is not possible here as it is already used.

I had experienced the data conflict while reading 89c51 code memory.As slave MCU will be in read mode (similar to signature byte read) and I send data on LCD using 4-bit mode the data conflict was there so I had to read data from slave MCU and than made it to write mode.Code will explain it in better way.

			ORL A,#0C0H             ;read mode
			MOV P2,A
			MOV P0,#0FFH    	;P0 INPUT PORT
			MOV R2,P0               ;reading from  
                                                ;slave       
			MOV P0,#0FFH
			MOV A,R1      	
			ORL A,#0E0H             ;write mode
			MOV P2,A			
									
			MOV A,R1
			CALL DISPLAY_DATA