Direct Address Mode (Da) - Samsung S3P80C5 User Manual

ADDRESSING MODES

DIRECT ADDRESS MODE (DA)

In Direct Address (DA) mode, the instruction provides the operand's 16-bit memory address. Jump (JP) and Call
(CALL) instructions use this addressing mode to specify the 16-bit destination address that is loaded into the PC
whenever a JP or CALL instruction is executed.
The LDC and LDE instructions can use Direct Address mode to specify the source or destination address for
Load operations to program memory (LDC) or to external data memory (LDE), if implemented.
NOTE:
3-10
Program or
Data Memory
Program Memory
Upper Address Byte
Lower Address Byte
dst/src
OPCODE
Sample Instructions:
LDC R5,1234H ; The values in the program address (1234H)
are loaded into register R5.
LDE R5,1234H ; Identical operation to LDC example, except that
external program memory is accessed.
LDE command is not available, because an external interface
is not implemented for the S3C80C5/C80C8/C804C.
Figure 3-10. Direct Addressing for Load Instructions
Memory
Address
Used
"0" or "1"
LSB Selects Program
Memory or Data Memory:
"0" = Program Memory
"1" = Data Memory
S3P80C5/C80C5/C80C8