2 power-on detection, 3 power reduction modes, Ip point – NXP Semiconductors P89LPC9321 UM10310 User Manual

Page 34: Table 15, Gives, Table 16, Nxp semiconductors

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UM10310

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User manual

Rev. 2 — 1 November 2010

34 of 139

NXP Semiconductors

UM10310

P89LPC9321 User manual

For correct activation of Brownout Detect, certain V

DD

rise and fall times must be

observed. Please see the data sheet for specifications.

5.2 Power-on

detection

The Power-On Detect has a function similar to the Brownout Detect, but is designed to
work as power initially comes up, before the power supply voltage reaches a level where
the Brownout Detect can function. The POF flag (RSTSRC.4) is set to indicate an initial
power-on condition. The POF flag will remain set until cleared by software by writing a
logic 0 to the bit. BOF (RSTSRC.5) will be set when POF is set.

5.3 Power

reduction

modes

The P89LPC9321 supports three different power reduction modes as determined by SFR
bits PCON[1:0] (see

Table 17

).

Table 15.

BOD Trip points configuration

BOE1
(UCFG1.5)

BOE0
(UCFG1.3)

BOICFG1
(BOICFG.1)

BOICFG0
(BOICFG.0)

BOD Reset

BOD
Interrupt

0

0

0

0

Reserved

0

0

0

1

0

0

1

0

0

0

1

1

0

1

0

0

0

1

0

1

2.2V

2.4V

0

1

1

0

2.2V

2.6V

0

1

1

1

2.2V

3.2V

1

0

0

0

Reserved

1

0

0

1

1

0

1

0

2.4V

2.6V

1

0

1

1

2.4V

3.2V

1

1

0

0

Reserved

1

1

0

1

1

1

1

0

1

1

1

1

3.0V

3.2V

Table 16.

BOD Reset and BOD Interrupt configuration

PMOD1/PMOD0(PCON[1:0])

BOI

(PCON.4)

EBO

(IEN0.5)

EA

(IEN0.7)

BOD

Reset

BOD
Interrupt

11 (total power-down)

X

X

X

N

N

≠ 11 (any mode other than total
power down)

0

X

X

Y

N

1

0

X

Y

N

X

0

Y

N

1

1

Y

Y

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