MT45W256KW16BEGB-708 WT Micron Technology Inc, MT45W256KW16BEGB-708 WT Datasheet - Page 22
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MT45W256KW16BEGB-708 WT
Manufacturer Part Number
MT45W256KW16BEGB-708 WT
Description
Manufacturer
Micron Technology Inc
Datasheet
1.MT45W256KW16BEGB-708_WT.pdf
(58 pages)
Specifications of MT45W256KW16BEGB-708 WT
Operating Temperature (max)
85C
Mounting
Surface Mount
Operating Temperature Classification
Commercial
Lead Free Status / Rohs Status
Compliant
Software Access to the Configuration Register
Figure 17:
PDF: 09005aef8329f3e3 / Source: 09005aef82e419a5
8mb_4mb_burst_cr1_0_p22z__2.fm - Rev. B 4/ 08 EN
Load Configuration Register
Notes:
Software access of the configuration registers uses a sequence of asynchronous READ
and asynchronous WRITE operations. The contents of the configuration registers can be
read or modified using the software sequence.
The configuration registers are loaded using a four-step sequence consisting of two
asynchronous READ operations followed by two asynchronous WRITE operations (see
Figure 17). The read sequence is virtually identical except that an asynchronous READ is
performed during the fourth operation (see Figure 18 on page 23). Note that a third
READ cycle of the highest address will cancel the access 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 (3FFFFh); the content at this address is not changed
by using this sequence.
The data value presented during the third operation (WRITE) in the sequence defines
whether the BCR or the RCR is to be accessed. If the data is 0000h, the sequence will
access the RCR; if the data is 0001h, the sequence will access the BCR. During the fourth
operation, DQ[15:0] transfer data into or out of bits 15–0 of the configuration registers.
The use of the software sequence does not affect the ability to perform the standard
(CRE-controlled) method of loading the configuration registers. However, the software
nature of this access mechanism eliminates the need for the control register enable
(CRE) pin. If the software mechanism is used, the CRE pin can simply be tied to V
port line often used for CRE control purposes is no longer required.
LB#/UB#
1. It is possible that the data stored at the highest memory location will be altered if the data
Address
at the falling edge of WE# is not 0000h or 0001h.
WE#
Data
OE#
CE#
4Mb: 256K x 16 Async/Page/Burst CellularRAM 1.0 Memory
Address
(MAX)
XXXXh
READ
Address
(MAX)
XXXXh
READ
22
RCR: 0000h
BCR: 0001h
Address
WRITE
(MAX)
Micron Technology, Inc., reserves the right to change products or specifications without notice.
0ns (MIN) Note 1
Address
WRITE
CR value
(MAX)
Don’t Care
in
Configuration Registers
©2008 Micron Technology, Inc. All rights reserved.
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