GMS81C1102 / GMS81C1202
17. Buzzer Output Function
The buzzer driver consists of 6-bit binary counter, the
buzzer register BUR and the clock selector. It generates
square-wave which is very wide range frequency (480
Hz~250 KHz at fxin = 4 MHz) by user programmable
counter.
Also, it is cleared by counter overflow and count up to out-
put the square wave pulse of duty 50%.
The bit 0 to 5 of BUR determines output frequency for
buzzer driving. Frequency calculation is following as
shown below.
Pin RB1 is assigned for output port of Buzzer driver by set-
ting the bit BUZO of RBFUNC to "1".
Oscillator Frequency
2 × Prescaler Ratio × (BUR + 1)
------------------------------------------------------------------------------
ꢀꢄꢅꢆ(ꢁꢂ) =
The 6-bit buzzer counter is cleared and start the counting
by writing signal to the register BUR. It is increased from
00H until it matches 6-bit register BUR.
The bits BUCK1, BUCK0 of BUR selects the source clock
from prescaler output.
ADDRESS : DEH
BUR
BUCK1
BUCK0
BUR5
BUR4
BUR3
BUR2
BUR1
BUR0
RESET VALUE : 11111111
Bit Manipulation Not Available
Input clock selection
00 : fxin
Buzzer Period Data
8
÷
01 : fxin 16
÷
10 : fxin 32
÷
11 : fxin 64
÷
8
÷
16
32
64
÷
÷
÷
COUNTER ( 6-bit )
fxin
MUX
F/F
COMPARATOR
BUCK[1:0]
RB1/BUZ PIN
BUZO
[RBFUNC.1]
BUR ( 6-bit )
Figure 17-1 Buzzer Driver
Jan. 2002 ver 2.0
53
HYNIX [ HYNIX SEMICONDUCTOR ]
