HT46R232/HT46C232

Rev. 1.40

22

November 23, 2005

Low Voltage Reset

- LVR

The microcontroller provides low voltage reset circuit in

order to monitor the supply voltage of the device. If the

supply voltage of the device is within the range

tomatically reset the device internally.

The LVR includes the following specifications:

original state to exceed 1ms. If the low voltage state

does not exceed 1ms, the LVR will ignore it and do not

perform a reset function.

²OR² function with the external RES

signal to perform chip reset.

operation at 4MHz system clock.

5 . 5 V

3 . 0 V

2 . 2 V

0 . 9 V

5 . 5 V

A / D c o n v e r s i o n t i m e

A / D c o n v e r s i o n t i m e

A / D c o n v e r s i o n t i m e

0 0 0 B

0 0 0 B

1 0 0 B

0 1 0 B

S T A R T

E O C B

P C R 2 ~

P C R 0

A C S 2 ~

A C S 0

P o w e r - o n

R e s e t

E n d o f A / D

c o n v e r s i o n

1 : D e f i n e P B c o n f i g u r a t i o n

2 : S e l e c t a n a l o g c h a n n e l

N o t e :

S t a r t o f A / D

c o n v e r s i o n

R e s e t A / D

c o n v e r t e r

A / D s a m p l i n g t i m e

1 0 0 B

0 0 0 B

S t a r t o f A / D

c o n v e r s i o n

R e s e t A / D

c o n v e r t e r

0 0 0 B

1 . P B p o r t s e t u p a s I / O s

2 . A / D c o n v e r t e r i s p o w e r e d o f f

t o r e d u c e p o w e r c o n s u m p t i o n

1 0 1 B

0 0 1 B

S t a r t o f A / D

c o n v e r s i o n

R e s e t A / D

c o n v e r t e r

d o n ' t c a r e

E n d o f A / D

c o n v e r s i o n

E n d o f A / D

c o n v e r s i o n

M i n i m u m o n e i n s t r u c t i o n c y c l e n e e d e d , M a x i m u m t e n i n s t r u c t i o n c y c l e s a l l o w e d

A / D s a m p l i n g t i m e

A / D s a m p l i n g t i m e

A/D Conversion Timing

5 . 5 V

0 . 9 V

0 V

R e s e t S i g n a l

R e s e t

* 1

* 2

N o r m a l O p e r a t i o n

R e s e t

L V R D e t e c t V o l t a g e

Low Voltage Reset

Note:

*1: To make sure that the system oscillator has stabilized, the SST provides an extra delay of 1024 system

clock pulses before entering the normal operation.

*2: Since low voltage state has to be maintained in its original state for over 1ms, therefore after 1ms delay,

the device enters the reset mode.