GMS81C2020/GMS81C2120
Hyundai Micro Electronics
17. Buzzer Output function
counter overflow
and count up to
output the square wave pulse of duty 50%.
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
The bit 0 to 5 of BUR determines output frequency for
buzzer driving. Frequency calculation is following as
shown below.
Pin R03 is assigned for output port of Buzzer driver by set-
ting the bit BUZO of R0FUNC to "1".
Oscillator Frequency
ꢐ × Prescaler Ratio × (ꢆꢇꢃ + ꢓ)
-------------------------------------------------------------------------------------
(ꢄꢅ) =
ꢀ
The 6-bit buzzer counter is cleared and start the counting
writing signal
00H until it matches 6-bit register BUR.
by
to the register BUR. It is increased from
The bits BUCK1, BUCK0 of BUR selects the source clock
from prescaler output.
ADDRESS : DEH
BUCK1
BUCK0
BUR5
BUR4
BUR3
BUR2
BUR1
BUR0
RESET VALUE : 11111111
BUR
Bit Manipulation Not Available
Input clock selection
00 : fXI
Buzzer Period Data
8
÷
01 : fXI 16
÷
10 : fXI 32
÷
11 : fXI 64
÷
8
÷
16
32
64
÷
÷
÷
Overflow
Detector
F/F
fXI
Counter ( 6-bit )
MUX
R03/BUZO
Writing to
BUR[5:0]
BUZO
[R0FUNC.3]
RESET
BUCK[1:0]
BUR ( 6-bit )
Figure 17-1 Buzzer Driver
62
preliminary
Nov. 1999 Ver 0.0
HYNIX [ HYNIX SEMICONDUCTOR ]
