X25F047

4

Operational Notes

The X25F047 powers up in the following state:

• The device is in the low power, standby state.

• A HIGH to LOW transition on CS is required to enter

an active state and receive an instruction.

• SO pin is at high impedance.

• The “Program Enable” latch is reset.

Data Protection

The following circuitry has been included to prevent inad-

vertant programming of data:

• The “Program Enable” latch is reset upon power-up.

• A PREN instruction must be issued to set the “Program

Enable” latch.

• CS must come HIGH at the proper clock count in order

to start a program cycle.

Table 1. Instruction Set and Block Lock Protection Byte Definition

7005 FRM T03.1

*Instructions are shown with MSB in leftmost position. Instructions are transferred MSB first.

Figure 2. Read Operation Sequence

Instruction

Format*

Instruction Name and Operation

0000 0110

PREN: Set the Program Enable Latch (Program Enable Operation)

0000 0100

PRDI: Reset the Program Enable Latch (Program Disable Operation)

0000 0001

PROGRAM STATUS Instruction - followed by:

Block Lock Protection Byte: (Figure 1)

0000 0000 --->NO PROTECT: ---------------------------------->None of the Array

0000 0001 --->PROTECT Q1: --- 0000h - 007Fh ---------->Lower Quadrant (Q1)

0000 0010 --->PROTECT Q2: --- 0080h - 00FFh----------->Q2

0000 0011 --->PROTECT Q3: --- 0100h - 017Fh----------->Q3

0000 0100 --->PROTECT Q4: --- 0180h - 01FFh----------->Upper Quadrant (Q4)

0000 0101 --->PROTECT H1: --- 0000h - 00FFh----------->Lower Half of the Array (H1)

0000 0110 --->PROTECT S0: --- 0000h - 000Fh----------->Lower Sector (S0)

0000 0111 --->PROTECT Sn: --- 01F0h - 01FFh----------->Upper Sector (Sn)

0000 0101

READ STATUS: Reads Block Lock Protection & nonvolatile write in progress status on SO Pin

0000 0010

PROGRAM: Program operation followed by address and data

0000 0011

READ: Read operation followed by address

0

1

2

3

4

5

6

7

8

9

CS

SCK

SI

SO

HIGH IMPEDANCE

READ INSTRUCTION

(1 BYTE)

BYTE ADDRESS (2 BYTE)

DATA OUT

15 14

3

2

1

0

20 21 22 23 24 25 26 27 28 29 30

7005 FRM F03.1

7

6

5

4

3

2

1

0