HN58X25128IAG/HN58X25256IAG

Write to Memory Array (WRITE):

As shown in the following figure, to send this instruction to the device, chip select (

S) is first driven low. The bits of

the instruction byte, address byte, and at least one data byte are then shifted in, on serial data input (D).

The instruction is terminated by driving chip select (

S) high at a byte boundary of the input data. In the case of the

following figure, this occurs after the eighth bit of the data byte has been latched in, indicating that the instruction is

Characteristics). At the end of the cycle, the Write In Progress (WIP) bit is reset to 0.

If, though, chip select (

S) continues to be driven low, as shown in the following figure, the next byte of the input data is

shifted in, so that more than a single byte, starting from the given address towards the end of the same page, can be

written in a single internal Write cycle.

Each time a new data byte is shifted in, the least significant bits of the internal address counter are incremented. If the

number of data bytes sent to the device exceeds the page boundary, the internal address counter rolls over to the

beginning of the page, and the previous data there are overwritten with the incoming data. (The page size of these

device is 64 bytes).

The instruction is not accepted, and is not executed, under the following conditions:

 If the Write Enable Latch (WEL) bit has not been set to 1 (by executing a Write Enable instruction just before)

 If a Write cycle is already in progress

 If the addressed page is in the region protected by the Block Protect (BP1 and BP0) bits.

Byte Write (WRITE) Sequence (1 Byte)

S

W

C

D

Q

16-Bit Address

Data Byte 1

01

2

3

4

5

6

7

0

1

2

3

13

14

15

8

9

10

20

21 22 23 24 25 26 27 28 29 30

31

High-Z

V

IH

V

IL

V

IH

V

IL

V

IH

V

IL

V

IH

V

IL

4

5

6

7

0

1

2

3

Instruction

Note:

1. Depending on the memory size, as shown in Address Range Bits table, the most significant address bits are

don’t care.

Rev.1.00, Nov.30.2006, page 15 of 20