Command 1: Display Mode Setting Commands

HT1668 provides 2 display mode settings as shown in the diagram below: As stated earlier a command is the first one byte

( b0 to b7 ) transmitted to HT1668 via the DIN Pin when STB is LOW. However, for these commands, the bit 3 to bit 6 (b2 to

b5) are ignored, bit 7 & bit 8 (b6 to b7) are given value of 0.

The Display Mode Setting Commands determine the number of segments and grids to be used (12 to 11 segments, 6 to 7

grids). A display command ON must be executed in order to resume display. If the same mode setting is selected, no command

execution is take place, therefore, nothing happens.

When Power is turned ON, the 7-grid, 11-segment modes is selected.

Command 2: Data Setting Commands

The Data Setting Commands executes the Data Write or Data Read Modes for HT1668. The data Setting Command, the

bits 5 and 6 (b4,b5) are ignored, bit 7 (b6) is given the value of 1 while bit 8 (b7) is given the value of 0. Please refer to the

diagram below.

When power is turned ON, bit 4 to bit 1 (b3 to b0) are given the value of 0.

HT1668 KEYMATRIX & KEYINPUT DATA STORAGE RAM

HT1668 Key Matrix consists of 10 x 2 array as shown below:

SG1/

SG2/

SG3/

SG4/

SG5/

SG6/

SG7/

SG8/

SG9/

SG10/

KS1

KS2

KS3

KS4

KS5

KS6

KS7

KS8

KS9

KS10

K1

K2

LED Driver IC

HT1668

www.artschip.com

4