PMR equ	0C4h	   ;power management register
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orl PMR,#00000001b ;internal 1kB sram enabled as data memory, DMEO (PMR.7) = 1
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movx A,@DPTR       ;read from SRAM (indexed by DPTR, range = 0000h - 03FFh)
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movx @DPTR,A       ;write to SRAM