3 Volt Intel® Advanced+ Boot Block Flash Memory Stacked-CSP Family
7.2.1
F-RP# Connected to System Reset
The use of F-RP# during system reset is important with automated program/erase devices since the
system expects to read from the flash memory when it comes out of reset. If a CPU reset occurs
without a flash memory reset, proper CPU initialization will not occur because the flash memory
may be providing status information instead of array data. Intel recommends connecting F-RP# to
the system CPU RESET# signal to allow proper CPU/flash initialization following system reset.
System designers must guard against spurious writes when F-VCC voltages are above VLKO. Since
both F-WE# and F-CE# must be low for a command write, driving either signal to VIH will inhibit
writes to the device. The CUI architecture provides additional protection since alteration of
memory contents can only occur after successful completion of the two-step command sequences.
The device is also disabled until F-RP# is brought to VIH, regardless of the state of its control
inputs.
By holding the device in reset (F-RP# connected to system PowerGood) during power-up/down,
invalid bus conditions during power-up can be masked, providing yet another level of memory
protection.
7.2.2
F-VCC, F-VPP and F-RP# Transition
The CUI latches commands as issued by system software and is not altered by F-VPP or F-CE#
transitions or WSM actions. Its default state upon power-up, after exit from reset mode or after
F-VCC transitions above VLKO (Lockout voltage), is read array mode.
After any program or block erase operation is complete (even after F-VPP transitions down to
VPPLK), the CUI must be reset to read array mode via the Read Array command if access to the
flash memory array is desired.
Figure 12. Example Power Supply Configurations
System Supply
System Supply
VCC
VPP
VCC
12 V Supply
VPP
Prot#
(Logic Signal)
10
≤ KΩ
12 V Fast Programming
Low-Voltage Programming
Absolute Write Protection With V PP
≤
VPPLK
Absolute Write Protection via Logic Signal
System Supply
(Note 1)
System Supply
VCC
VCC
VPP
VPP
12 V Supply
Low Voltage and 12 V Fast Programming
Low-Voltage Programming
NOTE: 1. A resistor can be used if the F-V supply can sink adequate current based on resistor value.
CC
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Datasheet
INTEL [ INTEL ]
