S-25A128B Просмотр технического описания (PDF) - Seiko Instruments Inc

Номер в каталоге

Компоненты Описание

производитель

S-25A128B

FOR AUTOMOTIVE 125°C OPERATION SPI SERIAL E2PROM

Seiko Instruments Inc 

Rev.1.3_01

FOR AUTOMOTIVE 125°C OPERATION SPI SERIAL E2PROM

S-25A128B

1. 2 BP1, BP0 (b3, b2) : Block Protect

Bit BP1 and BP0 are composed of the nonvolatile memory. The area size of Software Protect against WRITE

instruction is defined by them. Rewriting these bits is possible by the WRSR instruction. To protect the memory

area against the WRITE instruction, set either or both of bit BP1 and BP0 to "1". Rewriting bit BP1 and BP0 is

possible unless they are in Hardware Protect mode. Refer to " Protect Operation" for details of Block Protect.

1. 3 WEL (b1) : Write Enable Latch

Bit WEL shows the status of internal Write Enable Latch. Bit WEL is set by the WREN instruction only. If bit WEL

is "1", this is the status that Write Enable Latch is set. If bit WEL is "0", Write Enable Latch is in reset, so that this

IC does not receive the WRITE or WRSR instruction. Bit WEL is reset after these operations;

• The power supply voltage is dropping

• At power-on

• After performing WRDI

• After the completion of write operation by the WRSR instruction

• After the completion of write operation by the WRITE instruction

1. 4 WIP (b0) : Write In Progress

Bit WIP is read only and shows whether the internal memory is in the write operation or not by the WRITE or

WRSR instruction. Bit WIP is "1" during the write operation but "0" during any other status. Figure 10 shows the

usage example.

CS

WRITE or WRSR instruction

RDSR instruction

RDSR instruction

RDSR instruction

D2 D1 D0

RDSR

SI

S

R BB

W PP

D 10

RDSR

S

R BB

W PP

D 10

RDSR

S

R BB

W PP

D 10

SO

000 11

000 11

000 00

WEL, WIP

WEL, WIP

WEL, WIP

tPR

Figure 10 Usage Example of WEL, WIP Bits during Write

2. Write enable (WREN)

Before writing data (WRITE and WRSR), be sure to set bit Write Enable Latch (WEL). This instruction is to set bit

WEL. Its operation is below.

After selecting this IC by the chip select ( CS ), input the instruction code from serial data input (SI). To set bit WEL,

set this IC in the non-select status by CS at the 8th clock of the serial clock (SCK). To cancel the WREN instruction,

input the clock different from a specified value (n = 8 clock) while CS is in "L".

11

Share Link: