FS91M68

Low Battery Detection

Address

Name

Content

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

01DH

LowBatDct

lbEN

lowPwr

-

-

-

-

BiasSEL1 BiasSEL0

When resetting, lbEN=1, [BiasSEL1,BiasSEL0]=[0,0].

“lbEN=1” enables low batery detection, “lbEN=0” disables low batery detection.

When reading LowBatDct, lowPwr=1 is normal, lowPwr=0 indicates it is under preset low voltage.

Low Battery Detection option table：

BiasSEL1

BiasSEL0

Detect Voltage

0

0

1.329V

0

1

1.293V

1

0

1.260V

1

1

1.224V

***For various Low Voltage Detection option, the voltage detected might be different due to the slight

variation of the IC process.

I/O Port

Address

Name

Content

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

008H

PT1

PT1[7：0]

009H

PT1EN

PT1EN[7：4]

-

-

-

-

00AH

PT1PU

PT1PU[7：0]

00EH

PT1MR

BPE2

BPE1

CH_S

RF_EN

-

-

-

-

PT1[3：0] are input ports, with pull-up resistor enable control.

PT1[7：4] are I/O ports, when PT1EN[7：4] =0, PT1[7：4] will be the input ports.

when PT1EN[7：4] =1,PT1[7：4] will be the output ports

When system reset or initial start-up, the default value of PT1EN[*] is 0.

PT1EN[*]

PT1[*] setting

0

Input port

1

Output port

When PT1PU[N]=0, PT1[N] has no pull-up resister ; When PT1PU[N]=1, PT1[N] has pull-up resister

PT1PU[*]

PT1[*] setting

0

Internal pull-up disable

1

Internal pull-up enable

Rev. 1.3

11/24