X20C16
AUTOSTORE Feature
TheAUTOSTOREinstruction(EAS)totheSDPregister
setstheAUTOSTOREenablelatch,allowingtheX20C16
to automatically perform a store operation whenever
The AUTOSTORE feature automatically saves the con-
tents of the X20C16’s static RAM to the on-board bit-for-
V
V
falls below the AUTOSTORE threshold (V
).
CC
ASTH
2
bit shadow E PROM at power-down. This circuitry in-
must remain above the AUTOSTORE Cycle End
) for the duration of the store cycle
CC
suresthatnodataislostduringaccidentalpower-downs
orgeneralsystemcrashes, andisidealformicroproces-
sor caching systems, embedded software systems, and
general system back-up memory.
Voltage (V
ASEND
(t
). The detailed timing for this feature is illustrated
ASTO
in the AUTOSTORE timing diagram, below. Once the
AUTOSTORE cycle is initiated, all other device func-
tions are inhibited.
AUTOSTORE CYCLE Timing Diagrams
V
5
4
3
2
1
CC
V
ASTH
AUTOSTORE CYCLE IN PROGRESS
V
ASEND
t
ASTO
STORE TIME
TIME (ms)
CC
V
t
V
ASTH
0V
t
PUR
t
PUR
ASTO
AS
3826 FHD F14
AUTOSTORE CYCLE LIMITS
Symbol
X20C16
Parameter
Min.
Max.
Units
t
AUTOSTORE Cycle Time
2.5
4.3
ms
V
ASTO
V
V
AUTOSTORE Threshold Voltage
AUTOSTORE Cycle End Voltage
4.0
3.5
ASTH
V
ASEND
3826 PGM T15
12
XICOR [ XICOR INC. ]
