U634H256
Nonvolatile Memory Operations
Mode Selection
A13 - A0
(hex)
E
W
HSB
Mode
I/O
Power
Notes
H
L
L
L
X
H
L
H
H
H
H
X
X
X
Not Selected
Read SRAM
Write SRAM
Output High Z
Output Data
Input Data
Standby
Active
Active
Active
l
H
0E38
31C7
03E0
3C1F
303F
0FC0
Read SRAM
Read SRAM
Output Data
Output Data
Output Data
Output Data
Output Data
Output High Z
k, l
k, l
k, l
k, l
k, l
k
Read SRAM
Read SRAM
Read SRAM
Nonvolatile STORE
L
H
H
0E38
31C7
03E0
3C1F
303F
0C63
Read SRAM
Read SRAM
Output Data
Output Data
Output Data
Output Data
Output Data
Output High Z
Active
k, l
k, l
k, l
k, l
k, l
k
Read SRAM
Read SRAM
Read SRAM
Nonvolatile RECALL
X
X
L
X
STORE/Inhibit
Output High Z
I
CC2/Standby
m
k: The six consecutive addresses must be in order listed (0E38, 31C7, 03E0, 3C1F, 303F, 0FC0) for a Store cycle or (0E38, 31C7, 03E0, 3C1F,
303F, 0C63) for a RECALL cycle. W must be high during all six consecutive cycles. See STORE cycle and RECALL cycle tables and dia
grams for further details.
The following six-address sequence is used for testing purposes and should not be used: 0E38, 31C7, 03E0, 3C1F, 303F, 339C.
l: I/O state assumes that G ≤ VIL. Activation of nonvolatile cycles does not depend on the state of G.
m: HSB initiated STORE operation actually occurs only if a WRITE has been done since last STORE operation. After the STORE (if any)
completes, the part will go into standby mode inhibiting all operation until HSB rises.
Symbol
PowerStore Power Up RECALL/
No.
Conditions
Min. Max. Unit
Hardware Controlled STORE
Alt.
IEC
24 Power Up RECALL Durationn, e
25 STORE Cycle Duration
26 HSB Low to Inhibit One
27 HSB High to Inhibit Offe
28 External STORE Pulse Widthe
HSB Output Low Currente,o
tRESTORE
tHLQX
tHLQZ
650
10
µs
ms
µs
ns
ns
mA
µA
V
>
td(H)S
tdis(H)S
ten(H)S
tw(H)S
VCC 4.5 V
1
tHHQX
tHLHX
700
20
3
IHSBOL
IHSBOH
VSWITCH
.
HSB = VOL
HSB = VIL
HSB Output High Currente, o
5
60
Low Voltage Trigger Level
4.0
4.5
n: tRESTORE starts from the time VCC rises above VSWITCH
o: HSB is an I/O that has a week internal pullup; it is basically an open drain output. It is meant to allow up to 32 U634H256 to be ganged
together for simultaneous storing. Do not use HSB to pullup any external circuitry other than other U634H256 HSB pins.
7
April 21, 2004
ZMD [ Zentrum Mikroelektronik Dresden AG ]
