25A512 datasheet(8/34 Pages) MICROCHIP

8 / 34 page

25A512

DS22237C-page 8

Preliminary

 2010-2011 Microchip Technology Inc.

Read Sequence

The device is selected by pulling CS low. The 8-bit

READ

instruction is transmitted to the 25A512 followed

by the 16-bit address. After the correct READ instruction

and address are sent, the data stored in the memory at

the selected address is shifted out on the SO pin. The

data stored in the memory at the next address can be

read sequentially by continuing to provide clock pulses.

The internal Address Pointer is automatically incre-

mented to the next higher address after each byte of

data is shifted out. When the highest address is

reached (FFFFh), the address counter rolls over to

address 0000h allowing the read cycle to be continued

indefinitely. The READ instruction is terminated by rais-

ing the CS pin (Figure 2-1).

FIGURE 2-1:

READ SEQUENCE

SCK

23456789 10 11

21 22 23 24 25 26 27 28 29 30 31

15 14 13 12

210

765

43210

Instruction

16-bit Address

Data Out

High-Impedance

25A512 Datasheet(PDF) 8 Page - Microchip Technology