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Motor de Búsqueda de Datasheet de Componentes Electrónicos |
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GMS81C2112 Datasheet(PDF) 69 Page - Hynix Semiconductor |
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GMS81C2112 Datasheet(HTML) 69 Page - Hynix Semiconductor |
69 / 107 page ![]() GMS81C2112/GMS81C2120 JUNE. 2001 Ver 1.00 63 15. BUZZER FUNCTION The buzzer driver block consists of 6-bit binary counter, buzzer register BUR, and clock source selector. It gener- ates square-wave which has very wide range frequency (480Hz ~ 250kHz at fXIN= 4MHz) by user software. A 50% duty pulse can be output to R03/BUZO pin to use for piezo-electric buzzer drive. Pin R03 is assigned for output port of Buzzer driver by setting the bit 3 of R0FUNC(address 0F4H) to “1”. At this time, the pin R03 must be defined as output mode (the bit 3 of R0IO=1). Example: 5kHz output at 4MHz. LDM R0IO,#XXXX_1XXXB LDM BUR,#0011_0010B LDM R0FUNC,#XXXX_1XXXB X means don’t care The bit 0 to 5 of BUR determines output frequency for buzzer driving. Equation of frequency calculation is shown below. fBUZ: Buzzer frequency fXIN: Oscillator frequency Divide Ratio: Prescaler divide ratio by BUCK[1:0] BUR: Lower 6-bit value of BUR. Buzzer period value. The frequency of output signal is controlled by the buzzer control register BUR.The bit 0 to bit 5 of BUR determine output frequency for buzzer driving. Figure 15-1 Block Diagram of Buzzer Driver Figure 15-2 R0FUNC and Buzzer Register f BUZ f XIN 2 DivideRatio BUR 1 + () × × ---------------------------------------------------------------------------- = ÷8 ÷32 ÷16 ÷64 BUR R03/BUZO PIN R0FUNC Internal bus line R03 port data XIN PIN 6-bit binary 2 6 [0DEH] [0F4H] 0 1 F/F ÷2 Comparator Compare data 6-BIT COUNTER MUX 00 01 10 11 Port selection 3 BUR[5:0] BUR ADDRESS: 0DEH RESET VALUE: Undefined WW W W WW Source clock select 00: ÷ 8 01: ÷ 16 10: ÷ 32 11: ÷ 64 Buzzer Period Data R03/BUZO Selection R0FUNC ADDRESS : 0F4H RESET VALUE : ---- 0000B W - - 0: R03 port (Turn off buzzer) 1: BUZO port (Turn on buzzer) WW W BUCK1 BUCK0 WW - - BUZO EC0 INT1 INT0 |