7
4 Meg x 16 Async/Page/Burst Flash Memory Micron Technology, Inc., reserves the right to change products or specifications without notice.
MT28F642D18_3.p65 – Rev. 3, Pub. 8/02 ©2002, Micron Technology, Inc.
4 MEG x 16
ASYNC/PAGE/BURST FLASH MEMORY
ADVANCE
BALL DESCRIPTIONS
59-BALL FBGA
NUMBERS SYMBOL TYPE DESCRIPTION
E8, D8, C8, B8, A0–A21 Input Address Inputs: Inputs for the addresses during READ and WRITE
A8, B7, A7, C7, operations. Addresses are internally latched during READ and WRITE
A2, B2, C2, A1, cycles.
B1, C1, D2, D1,
D4, B6, A6, C6,
B3, C3
B4 CLK Input Clock: Synchronizes the Flash memory to the system operating
frequency during synchronous burst mode READ operations. When
configured for synchronous burst mode READs, address is latched on
the first rising (or falling, depending upon the read configuration
register setting) CLK edge when ADV# is active or upon a rising ADV#
edge, whichever occurs first. CLK is ignored during asynchronous
access READ and WRITE operations and during READ PAGE ACCESS
operations.
1
C4 ADV# Input Address Valid: Indicates that a valid address is present on the address
inputs. Addresses are latched on the rising edge of ADV# during READ
and WRITE operations. ADV# may be tied active during asynchronous
READ and WRITE operations.
1
A5 VPP Input Program/Erase Enable: [0.9V–2.20V or 11.4V–12.6V] Operates as input
at logic levels to control complete device protection. Provides factory
programming compatibility when driven to 11.4V–12.6V.
E7 CE# Input Chip Enable: Activates the device when LOW. When CE# is HIGH, the
device is disabled and goes into standby power mode.
F8 OE# Input Output Enable: Enables the output buffers when LOW. When OE# is
HIGH, the output buffers are disabled.
C5 WE# Input Write Enable: Determines if a given cycle is a WRITE cycle. If WE# is
LOW, the cycle is either a WRITE to the command state machine (CSM)
or to the memory array.
B5 RST# Input Reset: When RST# is a logic LOW, the device is in reset mode, which
drives the outputs to High-Z and resets the write state machine (WSM).
When RST# is at logic HIGH, the device is in standard operation. When
RST# transitions from logic LOW to logic HIGH, the device resets all
blocks to locked and defaults to the read array mode.
D6 WP# Input Write Protect: Controls the lock down function of the flexible locking
feature.
F7, E6, E5, G5, DQ0–DQ15 Input/ Data Inputs/Outputs: Inputs array data on the second CE# and WE#
E4, G3, E3, G1, Output cycle during PROGRAM command. Inputs commands to the
G7, F6, F5, F4, command user interface when CE# and WE# are active. DQ0–DQ15
D5, F3, F2, E2 output data when CE# and OE# are active.
D3 WAIT# Output Wait: Provides data valid feedback during continuous burst read
access. The signal is gated by OE# and CE#. This signal is always kept at
a valid logic level.
NOTE: 1. The CLK and ADV# inputs can be tied to VSS if the device is always operating in asynchronous or page mode. The WAIT#
signal can be ignored when operating in asynchronous or page mode, as it is always held at logic “1” or “0,” depending
on the RCR8 setting (see Table 9).
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