HT16515

Rev. 1.00

6

December 19, 2003

The key matrix is made up of a 16

´2 matrix, as shown below.

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 is of the CMOS output configuration.

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

starting from the 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 corresponding LED

lights up; when the bit is 1, the LED turns off. The data of

bits 4 through 7 are ignored.

Commands

Commands set the display mode and status of the VFD

driver.

The first 1 byte input to the HT16515 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 commands/

data being transmitted are not valid (however, the com-

mands/data previously transmitted remains valid).

These commands initialize the HT16515 and select

the number of segments and the number of grids

(1/4~1/12 duty, 16 to 24 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.

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 9 / K 9

b 0

b 1

b 2

b 3

b 4

b 5

b 6

b 7

S 5 / K 5

S 1 / K 1

S 1 0 / K 1 0

S 6 / K 6

S 2 / K 2

K e y 1 K e y 2

R e a d i n g S e q u e n c e

S 1 3 / K 1 3

S 1 4 / K 1 4

S 1 1 / K 1 1

S 7 / K 7

S 3 / K 3

S 1 2 / K 1 2

S 8 / K 8

S 4 / K 4

S 1 5 / K 1 5

S 1 6 / K 1 6

K e y 1 K e y 2

K e y 1 K e y 2

K e y 1 K e y 2

S 5 /

K 5

S 4 /

K 4

K E Y 1

S 3 /

K 3

S 1 /

K 1

S 2 /

K 2

S 1 1 /

K 1 1

S 1 0 /

K 1 0

S 9 /

K 9

S 6 /

K 6

S 7 /

K 7

S 8 /

K 8

S 1 2 /

K 1 2

K E Y 2

S 1 3 /

K 1 3

S 1 4 /

K 1 4

S 1 5 /

K 1 5

S 1 6 /

K 1 6

D o n ' t c a r e

0

0

M S B

L S B

b 0

b 1

b 2

b 3

S e l e c t s D i s p l a y M o d e

0 0 0 0 :

0 0 0 1 :

0 0 1 0 :

0 0 1 1 :

0 1 0 0 :

0 1 0 1 :

0 1 1 0 :

0 1 1 1 :

1 x x x :

4 d i g i t s , 2 4 s e g m e n t s

5 d i g i t s , 2 3 s e g m e n t s

6 d i g i t s , 2 2 s e g m e n t s

7 d i g i t s , 2 1 s e g m e n t s

8 d i g i t s , 2 0 s e g m e n t s

9 d i g i t s , 1 9 s e g m e n t s

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

1 1 d i g i t s , 1 7 s e g m e n t s

1 2 d i g i t s , 1 6 s e g m e n t s

Note:

Power-on status: 12-digit, 16 segment mode is

selected.