Datasheet

Extended Address Register

For devices whose A[MAX:MIN] equals A[23:0], the N25 family includes an extended ad-

dress register that provides a fourth address byte A[31:24], enabling access to memory

beyond 128Mb. Extended address register bit 0 is used to select the upper 128Mb seg-

ment or the lower 128Mb segment of the memory array.

Figure 9: Upper and Lower 128Mb Memory Array Segments

Upper 128Mb EAR<0> = A<24> = 1

EAR<0> = A<24> = 0

01FFFFFFh

01000000h

Bottom 128Mb 00FFFFFFh

00000000h

The PROGRAM and ERASE operations act upon the 128Mb segment selected in the ex-

tended address register.

The BULK ERASE operation erases the entire device.

The READ operation begins reading in the selected 128Mb segment, but is not bound

by it. In a continuous READ, when the last byte of the segment is read, the next byte out-

put is the first byte of the other segment as the operation wraps to 0000000h; Therefore,

a download of the whole array is possible with one READ operation. The value of the

extended address register does not change when a READ operation crosses the selected

128Mb boundary.

Table 15: Extended Address Register Bit Definitions

Note 1 applies to entire table

Bit Name Settings Description

7 A[31:25] 0 = Reserved –

0 A[24] 0 = Lower 128Mb segment

(default)

1 = Upper 128Mb segment

Enables 128Mb segmentation selection.

The default setting for this bit is determined by the non-

volatile configuration register bit 1. However, this set-

ting can be changed with the WRITE EXTENDED AD-

DRESS REGISTER command.

Note:

1. The extended address register is for an application that supports only 3-byte addressing.

It extends the device's first three address bytes A[23:0] to a fourth address byte A[31:24]

to enable memory access beyond 128Mb. The extended address register bit 0 enables

3V, 256Mb: Multiple I/O Serial Flash Memory

Nonvolatile and Volatile Registers

09005aef84566603

n25q_256mb_65nm.pdf - Rev. W 11/16 EN

Micron Technology, Inc. reserves the right to change products or specifications without notice.