Samsung KS57C2308 Manual page 141

KS57C2308/P2308/C2316/P2316
LDC
— Load Code Byte
LDC (Continued)
Examples: 2. The following instructions will load one of four values defined by the define byte (DB) directive
to the extended accumulator:
DISPLAY
If the instruction "LD WX,#01H" is executed in place of "LD WX,#00H", then
EA
If the instruction "LD WX,#02H" is executed in place of "LD WX,#00H", then
EA
3. Normally, the LDC EA, @EA and the LDC EA, @WX instructions reference the table data
on the page on which the instruction is located. If, however, the instruction is located at
address xxFFH, it will reference table data on the next page. In this example, the upper 4 bits
of the address at location 0200H is loaded into register E and the lower 4 bits into register A:
01FDH
01FFH
4. Here is another example of page referencing with the LDC instruction:
ORG 0500
DB 66H
DB 77H
DB 88H
DB 99H
LD WX,#00H
LDC EA,@WX
RET
address 0501H = 77H.
address 0502H = 88H.
ORG 01FDH
LD WX,#00H
LDC EA,@WX
ORG 0100
DB 67H
SMB 0
LD HL,#30H
LD WX,#00H
LDC EA,@WX
LD @HL,EA
; EA address 0500H = 66H
; E upper 4 bits of 0200H address
; A lower 4 bits of 0200H address
; Even number
; E upper 4 bits of 0100H address
; A lower 4 bits of 0100H address
; RAM (30H) 7, RAM (31H)
SAM47 INSTRUCTION SET
6
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