Samsung S3C84E5 user manual Indexed Addressing Mode, Offset, Ldc

ADDRESSING MODES S3C84E5/C84E9/P84E9

INDEXED ADDRESSING MODE (Continued)

	Program Memory
4-bit Working	OFFSET
	dst/src	x
Register Address
	OPCODE

Sample Instructions:

LDC R4, #04H[RR2]

LDE R4,#04H[RR2]

		Register File
MSB Points to
	RP0 or RP1
		RP0 or RP1	Selected
			RP points
~		~	to start of
			working
			register
			block

NEXT 2 Bits

Point to Working		Register
		Pair
Register Pair			16-Bit
	(1 of 4)
			address
		Program Memory	added to
LSB Selects			offset
		or
	+	Data Memory
8-Bits	16-Bits
	16-Bits	OPERAND	Value used in
			Instruction

;The values in the program address (RR2 + 04H) are loaded into register R4.

;Identical operation to LDC example, except that external program memory is accessed.

Figure 3-8. Indexed Addressing to Program or Data Memory with Short Offset

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