SST89E554 SST [Silicon Storage Technology, Inc], SST89E554 Datasheet - Page 20

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

Auxiliary Register (AUXR)
Auxiliary Register 1 (AUXR1)
Watchdog Timer Control Register (WDTC)
©2001 Silicon Storage Technology, Inc.
Location
Location
Location
0C0H
8EH
A2H
Symbol
EXTRAM
AO
Symbol
GF2
DPS
Symbol
WDOUT
WDRE
WDTS
WDT
SWDT
7
7
7
-
-
-
Function
0: Internal Expanded RAM access. For details, refer to “Data Memory” on page 12.
1: External data memory access.
0: Normal ALE
1: ALE is normally off. ALE is active only during a MOVX or MOVC instruction. This will reduce
EMI.
Function
General purpose user-defined flag.
DPTR registers select bit.
0: DPTR0 is selected.
1: DPTR1 is selected.
Function
Watchdog output enable.
0: Watchdog reset will not be exported on Reset pin.
1: Watchdog reset if enabled by WDRE, will assert Reset pin for 32 clocks.
Watchdog timer reset enable.
0: Disable watchdog timer reset.
1: Enable watchdog timer reset.
Watchdog timer reset flag.
0: External hardware reset clears the flag.
1: Hardware sets the flag on watchdog overflow.
Watchdog timer refresh.
0: Hardware resets the bit when refresh is done.
1: Software sets the bit to force a watchdog timer refresh.
Start watchdog timer.
0: Stop WDT.
1: Start WDT.
6
6
6
-
-
-
Flag can also be cleared by writing a 1.
Flag survives if chip reset happened because of watchdog timer overflow.
5
5
5
-
-
-
SST89E564 / SST89V564 / SST89E554 / SST89V554
WDOUT
4
4
4
-
-
20
WDRE
GF2
3
3
3
-
WDTS
2
2
0
2
-
EXTRAM
WDT
1
1
1
-
Preliminary Specifications
FlashFlex51 MCU
SWDT
DPS
AO
0
0
0
S71181-03-000 9/01
Reset Value
Reset Value
Reset Value
xxx00x00b
xxxx00x0b
xxxxxx00b
384