SM79164 Datasheet, PDF (9/26 Pages) SyncMOS Technologies,Inc – 8 - Bit Micro-controller with 64KB flash & 4KB RAM embedded

SyncMOS Technologies Inc.
June 2002
SM79164
With this bank mapping scheme, user can access entire 4k byte on-chip RAM with direct addressing method. That means
using the window area ($040~$07F), user can access any bank (64 byte) data of 4k byte on-chip RAM space which is
selected by BS[5:0] of data bank control register (DBANK, $86).
For example, user write #30h to $101 address:
MOV DBANK, #88H
; set bank mapping $040~$07f to $0100~$013f
MOV A, #30H
; store #30H to A
MOV 41H, A
; write #30H to $0101 address
Data Bank Control Register (DBANK, $86)
bit-7
bit-0
BSE
Unused
BS5
BS4
BS3
BS2
BS1
BS0
Read / Write: R/W
-
R/W
R/W
R/W
R/W
R/W
R/W
Reset value:
0
*
0
0
0
0
0
1
Data bank select enable bit BSE = 1 enables the data bank select function
Data bank select enable bit BSE = 0 disables the data bank select function
BS[5:0] setting will map $040~$07F RAM space to entire 4k byte on-chip RAM space.
Internal RAM Control Register (RCON, $85)
Read / Write:
Reset value:
bit-7
Unused
-
*
Unused
-
*
Unused
-
*
Unused
-
*
RAMS3
R/W
0
RAMS2
R/W
0
RAMS1
R/W
0
bit-0
RAMS0
R/W
0
SM79164 has 3840 byte on-chip RAM which can be accessed by external memory addressing method only. (By
instruction MOVX). The address space of instruction MOVX @Rn is determined by bit 3, bit2, bit1, bit 0
(RAMS3, RAMS2, RAMS1, RAMS0) of RCON. The default setting of RAMS3, RAMS2, RAMS1, RAMS0 bits
is 0000 (page0).
Specifications subject to change without notice,contact your sales representatives for the most recent information.
9/26
Ver 1.4 SM79164 06/02