MT45W4MW16PCGA-70 IT Micron Technology Inc, MT45W4MW16PCGA-70 IT Datasheet - Page 12

• Manufacturer Part Number: MT45W4MW16PCGA-70 IT
• Manufacturer: Micron Technology Inc

Specifications of MT45W4MW16PCGA-70 IT

• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Mounting: Surface Mount
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Compliant

Software Access to the Configuration Register
Figure 11:
PDF: 09005aef81f0698d / Source: 09005aef81f06935
64mb_asyncpage_cr1_0_p25z.fm - Rev. D 7/09 EN
Software Access Load Configuration Register
The contents of the CR can be read and modified using a software sequence. The nature
of this access mechanism may eliminate the need for the ZZ# ball.
If the software mechanism is used, ZZ# can simply be tied to V
cally used for ZZ# control purposes will no longer be required. However, ZZ# should not
be tied to V
using the software access sequence.
The CR is loaded using a four-step sequence consisting of two READ operations followed
by two WRITE operations (see Figure 11). The read sequence is virtually identical except
that an asynchronous READ is performed during the fourth operation (see Figure 12 on
page 13). Note that a third READ cycle of the highest address cancels the sequence until
a different address is read.
The address used during all READ and WRITE operations is the highest address of the
CellularRAM device being accessed (3FFFFFh for 64Mb); the content at this address is
changed by using this sequence. The data bus is used to transfer data into or out of bits
15–0 of the CR.
Writing to the CR using the software sequence modifies the function of ZZ#. Once the
software sequence loads the CR, the ZZ# level no longer enables PAR operation. PAR
operation will be updated whenever the software sequence loads a new value into the
CR. This ZZ# functionality will continue until the next time the device is powered up.
The operation of ZZ# is not affected if the software sequence is only used to read the
contents of the CR. The use of the software sequence does not affect the ability to
perform the standard (ZZ# controlled) method of loading the CR.
LB#/UB#
Address
Data
WE#
OE#
CE#
CC
Address
Q if the system will use DPD, since DPD cannot be enabled or disabled
(MAX)
XXXXh
READ
64Mb: 4 Meg x 16 Async/Page CellularRAM 1.0
Address
(MAX)
READ
XXXXh
12
Micron Technology, Inc., reserves the right to change products or specifications without notice.
CR: 0000h
Address
WRITE
(MAX)
CR value
Address
WRITE
(MAX)
Don’t Care
in
©2005 Micron Technology, Inc. All rights reserved.
CC
Q. The port line typi-
Device Registers