SM8958B Datasheet, PDF (21/49 Pages) SyncMOS Technologies,Inc – 256 bytes SRAM as standard 8052

SM8958B
8-Bit Micro-controller
32KB Flash
& 1KB RAM embedded
OME
MOVX @Ri instrcution
MOVX @DPTR instrcution
DPTR
{RAMS1,RAMS0}
DBANK[7]
DPTR
{RAMS1,RAMS0,@Ri}
{DBANK[3:0],direct
address}
MUX
A[9:0]
READ
WRITE
Bank 12-15 (64B x 4)
Bank 8-11 (64B x 4)
Bank 4-7 (64B x 4)
Bank 0-3 (64B x 4)
Scratchpad RAM
768
Bytes
On-chip 768B expanded RAM
1KB memory Space
Control Logic
SEL
Chip selection of on-chip expanded RAM and Scratchpad RAM
Fig.3-4: Access on-chip expanded RAM and scratchpad RAM with both in single 1KB addressing space scheme
Mnemonic: DBANK
7
6
5
BSE
-
-
Address: 86h
4
3
2
1
0
Reset
-
BS3
BS2
BS1
BS0
01H
BSE: Set 1 to enable data banking function.
BS[3:0]: One is selected from 16 pieces of 64B data memory bank.
BSE BS3 BS2 BS1 BS0
Mapped window : $40 - $7F
Physical address
Logically addressed range in 1K memory space
1
0
0
0
0
$000 – $03F
1
0
0
0
1
$040 – $07F
Scratchpad RAM
1
0
0
1
0
$080 – $0BF
( $00 – $FF )
1
0
0
1
1
$0C0 – $0FF
1
0
1
0
0
$100 – $13F
1
0
1
0
1
$140 – $17F
1
0
1
1
0
$180 – $1BF
1
0
1
1
1
$1C0 – $1FF
1
1
0
0
0
1
1
0
0
1
1
1
0
1
0
$200 – $23F
$240 – $27F
$280 – $2BF
Expanded RAM
( $000 – $2FF)
1
1
0
1
1
$2C0 – $2FF
1
1
1
0
0
$300 – $33F
1
1
1
0
1
$340 – $37F
1
1
1
1
0
$380 – $3BF
1
1
1
1
1
$3C0 – $3FF
0
x
x
x
x
Mapping is off
Mapping is off
Table3-2: Bank mapping address
Specifications subject to change without notice contact your sales representatives for the most recent information.
ISSFD-M085
Ver D SM8958B 08/07/2015
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