I am new to the 8051 micro. I have been given a project that has mixed C and assembly code. I am in the process of deciphering the code and commenting it for the future. So far everything has went smoothly, besides one small line of code that I just don't quite understand. I hope someone can shed some light for me.

RV120:
	MOV A,yerror		;put value of variable yerror into accumulator A
	MOV B,#0			;put 0x00 into B
	MOV R3,#59			;put 0x3B into register R3
	MOV R4,#0			;put 0x00 into register R4
	LCALL ?ugt			;call subroutine (not sure what ?ugt is)
	JNZ RV123			;jump to RV123 if accumulator A is not zero
	LJMP RV122			;else long jump to RV122
 

Can someone explain to me what this line is doing? I am not familiar with this at all.

LCALL ?ugt
 

Thanks in advance.

-John