SST89E554 SST [Silicon Storage Technology, Inc], SST89E554 Datasheet - Page 11

• Manufacturer Part Number: SST89E554
• Description: FlashFlex51 MCU
• Manufacturer: SST [Silicon Storage Technology, Inc]

FlashFlex51 MCU
SST89E564 / SST89V564 / SST89E554 / SST89V554
Preliminary Specifications
3.2 Program Memory Block Switching
The program memory block switching feature of the device
allows either Block 1 or the lowest 8 KByte of Block 0 to be
used for the lowest 8 KByte of the program address space.
SFCF[1:0] controls program memory block switching.
TABLE
©2001 Silicon Storage Technology, Inc.
SFCF[1:0]
FIGURE
01, 10, 11
00
FFFFH
0000H
3-1: SFCF V
3-2: P
Program Memory Block Switching
Block 1 is not visible to the PC;
Block 1 is reachable only via In-Application Programming from 000H - 1FFFH.
Block 1 is overlaid onto the low 8K of the program address space; occupying address locations 0000H - 1FFFH.
When the PC falls within 0000H - 1FFFH, the instruction will be fetched from Block 1 instead of Block 0.
Outside of 0000H - 1FFFH, Block 0 is used. Locations 0000H - 1FFFH of Block 0 are reachable through
In-Application Programming.
64 KByte
EA# = 0
External
ROGRAM
ALUES FOR
M
EMORY
DFFFH
FFFFH
7FFFH
1FFFH
E000H
8000H
2000H
0000H
P
ROGRAM
O
SFCF[1:0] = 00
RGANIZATION FOR
24 KByte
24 KByte
EA# = 1
External
8 KByte
8 KByte
Block 1
Block 0
Block 1
M
EMORY
B
11
LOCK
FFFFH
DFFFH
7FFFH
8000H
0000H
E000H
SST89E554
S
WITCHING FOR
SFCF[1:0] = 01
EA# = 1
24 KByte
32 KByte
External
8 KByte
Block 1
Block 0
AND
SST89V554
SST89E564/SST89V564
FFFFH
7FFFH
8000H
0000H
SFCF[1:0] = 10, 11
32 KByte
32 KByte
External
EA# = 1
Block 0
384 ILL F48b.3
S71181-03-000 9/01
T3-1.0 384
384