X5043 Datasheet, PDF (4/20 Pages) Xicor Inc. – CPU Supervisor with 4K SPI EEPROM

X5043/X5045
Resetting the V_TRIP Voltage
This procedure is used to set the V_TRIP to a “native”
voltage level. For example, if the current V_TRIP is 4.4V
and the new V_TRIP must be 4.0V, then the V_TRIP must
be reset. When V_TRIP is reset, the new V_TRIP is some-
thing less than 1.7V. This procedure must be used to
set the voltage to a lower value.
To reset the V_TRIP voltage, apply at least 3V to the V_CC
pin and tie the WP pin to the programming voltage V_P.
Then send a WREN command, followed by a write of
Data 00h to address 03h. CS going HIGH on the write
operation initiates the V_TRIP programming sequence.
Bring WP LOW to complete the operation.
Note: This operation also writes 00h to array address
03h.
Figure 2. Reset V_TRIP Level Sequence (V_CC > 3V. WP = 15–18V)
WP
V_PE = 15-18V
CS
SCK
0 1 23 4 56 7
SI
06h
WREN
Figure 3. Sample V_TRIP Reset Circuit
V_TRIP
Adj.
V_P
Adjust
Run
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
8 Bits
02h
Write
03h
Address
1
8
2 X5043 7
3 ^X5045 6
4
5
4.7K
RESET
00h
Data
µC
SCK
SI
SO
CS
REV 1.1.2 5/29/01
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Characteristics subject to change without notice. 4 of 20