September 2002

Specifications subject to change without notice,contact your sales representatives for the most recent information.

8/25

Ver 1.2

SM89516A 09/02

SyncMOS Technologies Inc.

SM89516A

BS3

BS2

BS1

BS0

040h~07fh map-

ping address

Note

0

0

0

0

000h~03fh

lower 128 byte RAM

0

0

0

1

040h~07fh

lower 128 byte RAM

0

0

1

0

080h~0bfh

higher 128 byte RAM

0

0

1

1

0c0h~0ffh

higher 128 byte RAM

0

1

0

0

0000h~003fh

on-chip expanded 768 byte RAM

0

1

0

1

0040h~007fh

“

0

1

1

0

0080h~00bfh

“

0

1

1

1

00c0h~00ffh

“

1

0

0

0

0100h~013fh

“

1

0

0

1

0140h~017fh

“

1

0

1

0

0180h~01bfh

“

1

0

1

1

01c0h~01ffh

“

1

1

0

0

0200h~023fh

“

1

1

0

1

0240h~027fh

“

1

1

1

0

0280h~02bfh

“

1

1

1

1

02c0h~02ffh

“

With this bank mapping scheme, user can access entire 1K 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 1K byte on-chip RAM space which is

selected by BS[3:0] 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