LLCALL (JKHL)     Far Call     Rabbit 4000 Instruction

Opcode	Instruction	Clocks	Operation
ED FA	LLCALL (JKHL)	19 (2,2,2,3,3,3,3,1)	(SP-1) = XPChigh (SP-2) = XPClow (SP-3) = PChigh (SP-4) = PClow PC = HL XPC = JK SP = SP-4

Flags				ALTD			IOI/IOE
S	Z	L/V	C	F	R	SP	S	D
-	-	-	-

Description

This instruction is similar to the LCALL instruction in that it transfers program execution to the subroutine address specified by the 16-bit constant mn and allows calls to made to a computed address in extended memory. The LLCALL instruction uses the 12-bit XPC of the Rabbit 4000 processor instead of the 8-bit XPC of earlier Rabbit processors. Note that the value of XPC and consequently the address space defined by the XPC is dynamically changed with the LCALL instructions.

In the LLCALL instruction, first XPC is pushed onto the stack, high-order byte first, then the low-order byte. Next, PC is pushed onto the stack, high-order byte first, then the low-order byte. Then PC is loaded with the data in HL and XPC is loaded with the data in JK. SP is then updated.