Application Circuits

Note: Capacitor C9 and C10 can adjust the accuracy of frequency

HT16562

Rev. 1.00

6

March 28, 2007

Time Adjustment Operation

Both the minutes and hour displays can be adjusted

separately or both together in a fast forward format.

The hour set pin, HS, and the minutes set pin, MS, are

used to make these adjustments. Both of these pins

are connected to internal pull-high resistors. Each

time one of these lines is pulled low, the respective

hour or minute value will increment by one, also if the

line is continuously held low then the respective value

will increment automatically at a rate of 2Hz. Both val-

ues will increment together if both lines are pulled low

simultaneously. Note that no carry functions will be im-

plemented when either the hour or minute value over-

flows.

A zero adjust function is also included within the de-

vice and is controlled by the ZA pin. This pin is con-

nected to an internal pull-high resistor. Pulling this line

low will reset both the internal minutes and seconds

value, however the way in which the display is reset

depends upon the present value of the display. If the

minute value is presently less than 30 the only the

second and minute values will be reset to zero and the

hour value remain unchanged. However if the minute

value is presently at a value of 30 or higher then when

the zero adjustment function is executed, a carry will

be implemented and the hour value will be incre-

mented by one. The following table illustrates a few

examples of this operation.

Zero Adjust Examples

Present Time

After Zero Adjust

Hr.

Min.

Sec.

Hr.

Min.

Sec.

1

30

00

2

00

00

2

00

00

2

00

00

2

29

59

2

00

00

2

30

00

3

00

00

2

59

59

3

00

00

3

29

59

3

00

00

3 f , 1 f

1

2

3 d , 1 d

Y 1

4 . 1 9 4 3 0 4 M H z

2 f

D I M 1

T E S T

3 e , 1 e

X T

3 c , 1 c

X T

1 / 2 D u t y

V F D P a n e l

2 c , c o l '

3 g , 1 g

3 e , 1 e

S W 7

3 g , 1 g

2 e

V D D

V S S

2 a , 2 d

3 c , 1 c

3 f , 1 f

G R 2

S W 5

S W 2

3 a , 1 a

G R 1

Z A

3 b , 1 b

3 d , 1 d

S W 8

6 4 H z

C 2

2 a , 2 d

2 c , c o l

F -

J u m p e r

1

2

3

M S

4 b , 4 c , 2 b

G R 2

V C C

F +

D I M 2

2 f

G R 1

H S

2 c , c o l

3 a , 1 a

R 1

2 e

2 g

E F

A / C

S W 6

B L A N K

4 b , 4 c , 2 b

S W 4

C 1

S W 1

3 b , 1 b

2 g

S W 3

J u m p e r