Name

ID

Command Code

D/C

Function

Def.

F1

100 101X-0000-X

C

Time base clock output: 1Hz

The WDT time-out flag after: 4s

F2

100 101X-0001-X

C

Time base clock output: 2Hz

The WDT time-out flag after: 2s

F4

100 101X-0010-X

C

Time base clock output: 4Hz

The WDT time-out flag after: 1s

F8

100 101X-0011-X

C

Time base clock output: 8Hz

The WDT time-out flag after: 1/2s

F16

100 101X-0100-X

C

Time base clock output: 16Hz

The WDT time-out flag after: 1/4s

F32

100 101X-0101-X

C

Time base clock output: 32Hz

The WDT time-out flag after: 1/8s

F64

100 101X-0110-X

C

Time base clock output: 64Hz

The WDT time-out flag after: 1/16s

F128

100 101X-0111-X

C

Time base clock output: 128Hz

The WDT time-out flag after: 1/32s

Yes

TEST

100 1110-0000-X

C

Test mode, user don

¢t use.

NORMAL

100 1110-0011-X

C

Normal mode

Yes

Note:

X : Don

¢t care

A5~A0 : RAM address

D3~D0 : RAM data

D/C : Data/Command mode

Def. : Power on reset default

All the bold forms, namely 110, 101, and 100, are mode commands. Of these, 100 indicates the command

mode ID. If successive commands have been issued, the command mode ID except for the first command will

be omitted. The source of the tone frequency and of the time base or WDT clock frequency can be derived from

a 32.768kHz crystal oscillator or an external 32768Hz clock. Calculation of the frequency is based on the sys-

tem frequency sources as stated above. It is recommended that the host controller should initialize the

HT16220 after power on reset, for power on reset may fail, which in turn leads to malfunctioning of the

HT16220.

HT16220

Rev. 1.90

13

October 12, 2009

PATENTED