點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

DM164

8x3-CHANNEL CONSTANT CURRENT LED DRIVERS

Version:A.002

Page 22

Data

[13]

PWM

MSB

0

0

‧‧‧

Data

[1]

Data

[0]

Data

[12]

PWM

MSB-1

PWM

LSB

PWM

LSB+1

14-bit

2-bit

16-bit

14-bit PWM Data

2-bit

Dummy Data

MSEL

DIN

GD[383]a

DCK

(DCKPH=L)

LTH

12

192

D&G

mode

GD mode

D&G[0]

384

1

384

2

DCK

(DCKPH=H)

12

192

384

1

384

2

10 GCK Latencies

. . .

. . .

GCK

2 GCK cycles

n

GD[382]a

GD[0]a

GD[383]b

GD[382]b

GD[0]b

Figure 14. Operating at n-bit PWM Grayscale Application Timing Diagram

c.2 IWAVE=”L” and 11~15-bit PWM application

When the DM164 operates at n-bit PWM grayscale application and IWAVE is set to ”L”

(where n is between 11~15). Users must add k-bit dummy data into the 16-bit GD mode

data of each channel (where k = 16-n). The 16-bit GD mode data format of each channel is

showed below:

Data

[n-1]

PWM

MSB

‧‧‧

0

0

‧‧‧

Data

[1]

Data

[0]

Data

[n-2]

PWM

MSB-1

PWM

LSB

PWM

LSB+1

n-bit

k-bit

16-bit

n-bit PWM Data

k-bit Dummy Data

The k-bit LSB of 16-bit GD mode data of each channel must be filled with all “0” ( k=16-n &

k < 6).

For example:

When the DM164 operates at 14-bit PWM grayscale application and IWAVE=”L”, the 2-bit

LSB of the 16-bit GD mode data must be filled with “0”. The 16-bit data format is showed

below: