SM5964_06 Datasheet, PDF (7/26 Pages) SyncMOS Technologies,Inc – 8-Bits Micro-controller 64KB ISP flash & 1KB RAM embedded

SyncMOS Technologies International, Inc.
1.2 Data Memory
SM5964
8-Bits Micro-controller
64KB ISP flash & 1KB RAM embedded
The SM5964 has 1K bytes on-chip RAM, 256 bytes of it are the same as general 8052 internal memory structure while
the expanded 768 bytes on-chip RAM can be accessed by external memory addressing method (by instruction
MOVX.).
1.2.1 Data Memory - Lower 128 byte ($00 to $7F)
Data Memory $00 to $FF is the same as 8052.
The address $00 to $7F can be accessed by direct and indirect addressing modes.
Address $00 to $1F is register area.
Address $20 to $2F is memory bit area.
Address $30 to $7F is for general memory area.
1.2.2 Data Memory - Higher 128 byte ($80 to $FF)
The address $80 to $FF can be accessed by indirect addressing mode .
Address $80 to $FF is data area.
1.2.3 Data Memory - Expanded 768 bytes ($0000 to $02FF)
From external address $0000 to $02FF is the on-chip expanded RAM area, total 768 bytes. This area can be accessed
by external direct addressing mode (by instruction MOVX).
If the address of instruction MOVX @DPTR is larger than $02FF then SM5964 will generate the external memory
control signal automatically. The bit 1 (OME) of special function register $BF (SCONF) can enable or disable this
expanded 768 byte RAM. The default setting of OME bit is 1 (enable).
Specifications subject to change without notice contact your sales representatives for the most recent information.
Ver 2.2 SM5964 08/2006
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