HT16512

Rev. 1.40

5

May 3, 2005

The data of each key is stored as illustrated below, and

is read with the read command, starting from the least

significant bit.

LED Port

The LED port belongs to the CMOS output configura-

tion.

Data is written to the LED port with the write command,

starting from the least port

¢s least significant bit. In our

application (see application circuits), the user adopts an

internal NMOS device to a driver LED component by

connecting VDD. When a bit of this port is 0, the corre-

sponding LED lights; when the bit is 1, the LED turns off.

The data of bits 5 through 8 are ignored.

SW Data

HT16512 provides an extra 4-bit general input port. The

SW data is provided with available binary code. The SW

data is read with the read command, starting from the

least significant bit. Bits 5 through 8 of the SW data are

0.

Commands

Commands set the display mode and status of the VFD

driver.

The first 1 byte input to the HT16512 through the DI pin

after the CS pin has fallen, is regarded as a command. If

CS is set high while commands/data are transmitted,

serial communication is initialized, and the com-

mands/data being transmitted are not valid (however,

the commands/data previously transmitted remains

valid).

These commands initialize the HT16512 and select

the number of segments and the number of grids

(1/4~1/11 duty, 11 segments to 16 segments).

When these commands are executed, the display is

forcibly turned off, and key scanning is also stopped.

To resume display, the display command

²ON² must

be executed. If the same mode is selected, nothing

happens.

These commands set the data write and data read

modes.

These commands set the address of the display mem-

ory.

If address 16H or higher is set, data is ignored until a

valid address is set.

M S B

L S B

b 0

b 1

b 2

b 3

L E D 0

L E D 1

L E D 2

L E D 3

D o n ' t c a r e

S 4 / K 4

b 0 b 1 b 2 b 3 b 4 b 5 b 6 b 7

S 2 / K 2

S 0 / K 0

S 5 / K 5

S 3 / K 3

S 1 / K 1

K 0 ~ K 3

K 0 ~ K 3

R e a d i n g f i r s t

R e a d i n g l a s t

S W 0

S W 1

S W 2

S W 3

M S B

L S B

b 0

b 1

b 2

b 3

0

0

0

0

D i s p l a y m o d e s e t t i n g s

0 0 0 : 4 d i g i t s , 1 6 s e g m e n t s

0 0 1 : 5 d i g i t s , 1 6 s e g m e n t s

0 1 0 : 6 d i g i t s , 1 6 s e g m e n t s

0 1 1 : 7 d i g i t s , 1 5 s e g m e n t s

1 0 0 : 8 d i g i t s , 1 4 s e g m e n t s

1 0 1 : 9 d i g i t s , 1 3 s e g m e n t s

1 1 0 : 1 0 d i g i t s , 1 2 s e g m e n t s

1 1 1 : 1 1 d i g i t s , 1 1 s e g m e n t s

D o n ' t c a r e

0

0

M S B

L S B

b 0

b 1

b 2

D a t a w r i t e a n d r e a d m o d e s e t t i n g s

0 0 : W r i t e d a t a t o d i s p l a y m e m o r y

0 1 : W r i t e d a t a t o L E D p o r t

1 0 : R e a d k e y d a t a

1 1 : R e a d S W d a t a

0

1

D o n ' t c a r e

A d d r e s s i n c r e m e n t m o d e s e t t i n g s ( d i s p l a y m e m o r y )

0 : I n c r e m e n t s a d d r e s s a f t e r d a t a h a s b e e n w r i t t e n

1 : F i x e s a d d r e s s

T e s t m o d e s e t t i n g s

0 : N o r m a l m o d e

1 : T e s t m o d e , u s e r d o n ' t u s e

M S B

L S B

b 0

b 1

b 2

b 3

A d d r e s s ( 0 0 H ~ 1 5 H )

1

1

M S B

L S B

b 0

b 1

b 2

b 3

b 4

D o n ' t c a r e

D i m m i n g q u a n t i t y s e t t i n g s

0 0 0 : S e t p u l s e w i d t h t o 1 / 1 6

0 0 1 : S e t p u l s e w i d t h t o 2 / 1 6

0 1 0 : S e t p u l s e w i d t h t o 4 / 1 6

0 1 1 : S e t p u l s e w i d t h t o 1 0 / 1 6

1 0 0 : S e t p u l s e w i d t h t o 1 1 / 1 6

1 0 1 : S e t p u l s e w i d t h t o 1 2 / 1 6

1 1 0 : S e t p u l s e w i d t h t o 1 3 / 1 6

1 1 1 : S e t p u l s e w i d t h t o 1 4 / 1 6

1

0

D o n ' t c a r e

T u r n s o n / o f f d i s p l a y

0 : D i s p l a y o f f ( k e y s c a n c o n t i n u e s )

1 : D i s p l a y o n

M S B

L S B

b 0

b 1

b 2

b 3