ASAHI KASEI

[AK6516C]

DAP05E-00

2005/03

- 7 -

WRSR (WRITE STATUS REGISTER)

The WRSR instruction can set the Write Protect Block size of the memory array.

AK6516C has 4 Blocks of memory arrays.

Write Protect Block size can be selected from 1/4, 1/2

and whole memory array.

The block, which is set by Write Protect, is Read only.

BP0 bit, BP1 bit, and WPEN bit are programmable with EEPROM memory cell bits.

The

characteristics of those bits (WREN, tE/W, RDSR) are same as the EEPROM memory array.

WP pin function can be set by WPEN (WRITE PROTECT ENABLE) bit which is defined by WRSR

function.

When WP pin is low level and WPEN bit is "1", the WRITE function to Status register,

which has WPEN bit and BP0/BP1 bit, and to Write Disable Block is not performed.

Then WRITE

function is performed only to the Write enable block.

When WP pin is "1" or WPEN bit is "0", then the function of WP pin is disabled and WRITE function

to the Status Register is performed.

WREN function should be done before WRSR function.

And after the Programming function,

AK6516C becomes Write Disable status automatically.

WRSR

WPEN

Bit

WP

Pin

WEN

Bit

Write Protected

Block

Not Protected

Block

Status Register

0

X

0

WRITE Disable

WRITE Disable

WRITE Disable

0

X

1

WRITE Disable

WRITE Enable

WRITE Enable

1

Low

0

WRITE Disable

WRITE Disable

WRITE Disable

1

Low

1

WRITE Disable

WRITE Enable

WRITE Disable

X

High

0

WRITE Disable

WRITE Disable

WRITE Disable

X

High

1

WRITE Disable

WRITE Enable

WRITE Enable

Table 3. WPEN function

Status Register bits

BP1

BP0

Write Protected

Block

0

0

none

0

1

6000h - 7FFFh

1

0

4000h - 7FFFh

1

1

0000h - 7FFFh

Table 4. Write Protected Block Size

Hi-Z

0123456789

10

11

12

13

14

15

0

0

0

0

00

1

Bit1

Bit2

Bit3

Bit4

Bit5

Bit6

Bit7

Bit0

CS

SCK

SI

SO

X = don’t care

X