Samsung KS57C2308 Call Call Procedure, Call Operation, Operand Operation Summary Bytes Cycles

KS57C2308/P2308/C2316/P2316 SAM47 INSTRUCTION SET

CALL — Call Procedure

CALL Operation:

dst

Operand	Operation Summary	Bytes	Cycles
ADR14	Call direct in page (14-bits)	3	4

Description: CALL calls a subroutine located at the destination address. The instruction adds three to the program counter to generate the return address and then pushes the result onto the stack, decreasing the stack pointer by six. The EMB and ERB are also pushed to the stack. Program execution continues with the instruction at this address. The subroutine may therefore begin anywhere in the full 16-Kbyte program memory address space.

Operand				Binary Code						Operation Notation
ADR14	1	1	0		1	1	0	1	1	[(SP–1) (SP–2)] ← EMB, ERB
	0	1	a13		a12	a11	a10	a9	a8	[(SP–3) (SP–4)] ← PC7–0
										[(SP–5) (SP–6)] ← PC13-8
	a7	a6	a5		a4	a3	a2	a1	a0	PC13–0 ← ADR13–0
										(SP) ← (SP)–6

Example: The stack pointer value is 00H and the label “PLAY” is assigned to program memory location 0E3FH. Executing the instruction

CALL PLAY

at location 0123H will generate the following values:

SP	=	0FAH
0FFH	=	0H
0FEH	=	EMB, ERB
0FDH	=	2H
0FCH	=	6H
0FBH	=	0H
0FAH	=	1H
PC	=	0E3FH

Data is written to stack locations 0FFH–0FAH as follows:

SP – 6 (0FAH)		PC11–PC8
SP – 5 (0FBH)	0	0	PC13	PC12
SP – 4 (0FCH)		PC3–PC0
SP – 3 (0FDH)		PC7–PC4
SP – 2 (0FEH)	0	0	EMB	ERB
SP – 1 (0FFH)	0	0	0	0
SP ← (00H)

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