BU21009MUV

Technical Note

11/13

www.rohm.com

2009.04 - Rev.B

© 2009 ROHM Co., Ltd. All rights reserved.

【

FAh : Simultaneous Press and Idle Mode Entry】

Name:

CMD

Address:

FAh

Description:

INTERMIT_EN : Intermittent and the drive are enable. ：

Whether intermittent is driven at the idol mode is selected.

1：Intermittent is driven. 0：Intermittent is not driven.

Initial state：Intermittent is driven.

IDLE_T[3:0] : non-detect time-out setting ：

This sets the time the chip takes to go from normal mode to idle mode in a period key inactivity.

Duration = system clock x 2

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

FAh

-

-

-

INTERMIT_EN

IDLE_T[3]

IDLE_T[2]

IDLE_T[1]

IDLE_T[0]

R/W

-

-

-

W

W

W

W

W

Initial val.

-

-

-

1

0

1

1

1

【

FBh : Gain Setting, Filter Function】

Name:

GAIN_FILTER

Address:

FBh

Description:

Gain adjustment and setting of noise filter function.

GAIN[2:0] : gain setting：

It uses it for the gain adjustment in eight stages. Initial adjustment value：x1

GAIN[2:0]

000

001

010

011

100

101

110

111

Adjustment value

x 1

x 4.22

x 8.4

x 16.5

x 23

x 46

x 69

x 92

FILTER_EN : Filter enable ：

Enables/disables setting of noise filter function

1 : enabled 0 : disabled Initial state : disabled

DELTA[3:0] : Filter follow count setting ：

The follow count to which the noise filter function is effective is set.

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

FBh

GAIN[2]

GAIN [1]

GAIN[0]

FILTER_EN

DELTA[3]

DELTA[2]

DELTA[1]

DELTA[0]

R/W

W

W

W

W

W

W

W

W

Initial val.

0

0

0

0

0

0

1

0

【

FCh : Switch OFF -> ON Threshold】

Name:

TH_ON

Address:

FCh

Description: This register provides a threshold value for determining if a sensor has transitioned from OFF to ON.

This is relative value from reference value (128d). So the absolute value of threshold is 128d + ON[6:0].

It makes a threshold value between TH_ON and TH_OFF.

TH_ON must be bigger than TH_OFF (TH_ON >= TH_OFF)

Maximum threshold is 256d and minimum value is 128d.

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

FCh

-

ON[6]

ON[5]

ON[4]

ON[3]

ON[2]

ON[1]

ON[0]

R/W

-

W

W

W

W

W

W

W

Initial val.

-

0

0

1

0

0

0

0