HT45RM03

Rev. 1.10

28

February 16, 2007

Polling_EOC:

sz

EOCB

; poll the ADCR register EOCB bit to detect end of A/D conversion

jmp

polling_EOC

; continue polling

mov

a,ADRH

; read conversion result high byte value from the ADRH register

mov

adrh_buffer,a

; save result to user defined memory

mov

a,ADRL

; read conversion result low byte value from the ADRL register

mov

adrl_buffer,a

; save result to user defined memory

:

:

jmp

start_conversion

; start next A/D conversion

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

Comparator

There is one Comparator in the device. The CMPEN bits

is used as the enable or disable bits, if the CMPEN is

cleared to

²0², the Comparator is disabled, the

PA1/CVINP, PA2/CVINN, PA3/COUT are all GPIO pins,

if the CMPEN is set to

²1², the Comparator is enabled,

the PA1/CVINP, PA2/CVINN are Comparator input pins,

PA3/COUT is a Comparator output pin.

The CVINP, CVINN and COUT are pin-shared with PA1,

PA2 and PA3. Once the Comparator function is used,

the internal registers related to PA1, PA2 cannot be

used, PA3 can be used as input only( if the COUTEN is

²1²), and the PA1, PA2 I/O function, PA3 output function

and pull-high resistor are disabled automatically(if the

COUTEN is

²1²). Once the Comparator function is used,

the PA3 is the GPIO when the COUTEN is

²0². Software

instructions determine the Comparator function to be

used.

C R S

0

0

1

1

C O F M

0

1

0

1

S 1

O N

O F F

O N

O N

S 2

O N

O N

O N

O F F

S 3

O F F

O N

O F F

O N

C M P O P

I n t e r r u p t

P A 1 / C V I N P

C O F 0 ~ C O F 3

C M P E N

S 1

S 2

S 3

P A 2 / C V I N N

P A 3 / C O U T

Comparator Block Diagram