HT16220
Name
ID
Command Code
D/C
Function
Def.
Time base clock output: 1Hz
F1
1 0 0 101X-0000-X
1 0 0 101X-0001-X
1 0 0 101X-0010-X
1 0 0 101X-0011-X
1 0 0 101X-0100-X
1 0 0 101X-0101-X
1 0 0 101X-0110-X
1 0 0 101X-0111-X
C
The WDT time-out flag after: 4s
Time base clock output: 2Hz
F2
C
C
C
C
C
C
C
The WDT time-out flag after: 2s
Time base clock output: 4Hz
F4
The WDT time-out flag after: 1s
Time base clock output: 8Hz
F8
The WDT time-out flag after: 1/2s
Time base clock output: 16Hz
F16
F32
F64
The WDT time-out flag after: 1/4s
Time base clock output: 32Hz
The WDT time-out flag after: 1/8s
Time base clock output: 64Hz
The WDT time-out flag after: 1/16s
Time base clock output: 128Hz
F128
Yes
Yes
The WDT time-out flag after: 1/32s
TEST
1 0 0 1110-0000-X
1 0 0 1110-0011-X
C
C
Test mode, user don¢t use.
NORMAL
Normal mode
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 1 1 0, 1 0 1, and 1 0 0, are mode commands. Of these, 1 0 0 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 32kHz clock. Calculation of the frequency is based on the system
frequency sources as stated above. It is recommended that the host controller should initialize the HT16220 af-
ter power on reset, for power on reset may fail, which in turn leads to malfunctioning of the HT16220.
Rev. 1.20
11
May 19, 2004
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
