Flash Vpp Recommendations - Intel 440GX Design Manual

(WP# pin not available on 8-Mbit 44-lead PSOP. In this package, treat as if the WP# pin is
internally tied low, effectively eliminating the last row of the table below.)
•
Use either A16 or A17 inversion for both the 2Mbit or 4Mbit to differentiate between recovery
and normal modes.
•
If migrating a BV design to the lower cost B5 device, Application Brief AB-65 "Migrating
SmartVoltage Boot Block Flash Designs to Smart 5 Flash" is available (Order#292194).
Table 3-13. Flash Vpp Recommendations
VPP
VIL
VPPLK
VPPLK
VPPLK
VPPLK
NOTES:
1. V is specified at 1.5V(maximum).
PPLK
2. V is specified at logic low.
IL
3. V is specified at logic high.
IH
4. V is specified at 12V 5%.
HH
•
Use SUSA# to drive the flash RP# pin into the deep power-down mode when system is in the
suspend states.
•
(SUSA# Alternative) Use system "POWEROK" or "POWERGOOD" signal to drive flash RP#
to keep device in deep power down during power-up only (write protection). For systems not
needing power saving modes.
•
Connect BYTE# to GND for byte-wide mode operation if x16 device is used.
•
Use a 0.01mf - 0.1mf ceramic capacitor connected between each Vcc and GND, and between
its Vpp and GND. These high frequency, inherently low inductance capacitors should be
placed as close as possible to the package leads.
•
Add information on how BIOSCS# elevates the need for control logic and GPO[x] control on
WE#
•
Add information on ISA load consideration and the reduction of the X-bus drivers/control
Figure 3-7
®
Intel 440GX AGPset Design Guide
RP# WP#
X X All Blocks Locked (Programming)
VIL X All Blocks Locked (All operations)
VHH X All Blocks Unlocked (All operations)
VIH VIL Boot Block Locked (Programming)
VIH VIH All Blocks Unlocked (All operations)
illustrates the recommended layout for Intel's flash devices in desktop designs:
Write Protection
Design Checklist
3-27