Rev. 1.00

24

November 16, 2011

HT16L21

Command Summary

Software Reset Command

ThiscommandisusedtoinitializetheHT16L21device.

Function

Byte (MSB)

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1 (LSB)

Bit0

Note R/W

Def

Soft Reset Command

1

0

1

0

1

0

1

0

—

W

—

Note:

● When this software reset command is executed, all the command registers are initialized to the default values.

● After the reset command is executed, the device will experience an internal initialization for 1ms.

● Normal operation can be executed after the device initialization is complete.

● During the initialization period, no commands can be executed.

● If the programmed command is not defined, the function will not be affected.

The status of the internal circuits after initialization is as follows:

● The 1/3 bias drive mode is selected.

● The system oscillator and the LCD bias generator are in an off state.

● The LCD display is in an off state and the integrated regulator is disabled.

● The segment/LED shared pin is setup as a segment pin.

● The frame frequency is set to 64Hz.

● The blinking function is switched off.

Drive Mode Command

Function

Byte (MSB)

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1

(LSB)

Bit0 Note R/W Def

Drive mode setting command

1

0

0

0

0

0

1

0

—

W

—

X

X

SP1 SP0

X

X

X

Bias

—

W

00H

Note:

Bit0

Bias

0

1/3 bias

1

1/2 bias

SP1

SP0

Segment/LED shared pin selected

Segment 28~31/LED3~0

Segment 24~27/LED7~4

0

X

Set as segment pins

Set as segment pins

1

0

Set as LED pins

Set as segment pins

1

1

Set as LED pins

Set as LED pins

● Power on status: The1/3 bias drive mode is selected and also the segment output pins are selected.

● If the programmed command is not defined, the function will not be affected.