HT16270
T im e B a s e
C lo c k S o u r c e
/2 5 6
V
C L R T im e r
D D
T IM E R
E N /D IS
IR Q
W D T E N /D IS
D
C K
R
Q
IR Q
E N /D IS
W D T
/4
C L R
W D T
Timer and WDT configurations
If an external clock is selected as the source of
system frequency, the SYS DIS command turns
out invalid and the power down mode fails to be
carried out until the external clock source is re-
moved.
Buzzer tone output
A simple tone generator is implemented in the
HT16270. The tone generator can output a pair
of differential driving signals on the BZ and BZ
which are used to generate a single tone.
Command format
The HT16270 can be configured by the software
setting. There are two mode commands to con-
figure the HT16270 resource and to transfer
the LCD display data.
Name
TONE OFF
TONE 4K
TONE 2K
Command Code
0000-1000-X
010X-XXXX-X
0110-XXXX-X
Turn-off tone output
Turn-on tone output, tone frequency is 4kHz
Turn-on tone output, tone frequency is 2kHz
The following are the data mode ID and the
command mode ID:
Operation
READ
WRITE
READ-MODIFY-WRITE
COMMAND
Mode
Data
Data
Data
ID
110
101
101
Command 1 0 0
If successive commands have been issued, the
command mode ID can be omitted. While the
system is operating in the non-successive com-
mand or the non-successive address data mode,
the CS pin should be set to
²1²
and the previous
operation mode will be reset also. The CS pin
returns to
²0²,
a new operation mode ID should
be issued first.
Function
9
April 21, 2000
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
