SyncMOS Technologies Inc.
September 2002
SM8958A
1.2.1 Data Memory - Lower 128 byte ($00 to $7F, Bank 0 & Bank 1)
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, Bank 2 & Bank 3)
The address $80 to $FF can be accessed by indirect addressing mode or by bank mapping direct addressing mode.
Address $80 to $FF is data area.
1.2.3 Data Memory - Expanded 768bytes ($0000 to $02FF, Bank 4 ~ Bank 15)
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) or by bank mapping direct addressing mode as described below:
1.3 Bank mapping direct addressing mode
:
We provide RAM bank address ‘40H~7FH’ as mapping window which allow user access all the 1KB on-chip RAM through
this RAM bank address.
That means using direct addressing mode can access all the 1KB on-chip RAM. Please see next page for the mapping
mode table.
Specifications subject to change without notice,contact your sales representatives for the most recent information.
7/25
Ver 1.0
PID 8958A 09/02
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
