ADDRESSING MODES

S3F80JB

 

 

INDIRECT REGISTER ADDRESSING MODE (Continued)

4-bit Working Register Address

Example Instruction References either Program Memory or Data Memory

Program Memory

dst

src

OPCODE

MSB Points to

RP0 or RP1

Next 2-bit Point

to Working

Register Pair

(1 of 4)

LSB Selects

Value used in Instruction

Register File

RP0 or RP1

Register

Pair

Program Memory

or

Data Memory

OPERAND

Selected RP points to start of working register block

16-Bit address points to program memory or data memory

Sample Instructions:

LCD

R5,@RR6

LDE

R3,@RR14

LDE

@RR4, R8

;Program memory access

;External data memory access

;External data memory access

NOTE: LDE command is not available, because an external interface is not implemented for the S3F80JB.

Figure 3-6. Indirect Working Register Addressing to Program or Data Memory

3-6

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Samsung S3F80JB manual Lcd