Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

PIN HANEL

DESCRIPTION XTAL1 and

XTAL2(cont’)

‰The speed of 8051 refers to the maximum oscillator frequency connected to XTAL

¾ex. A 12-MHz chip must be connected to a crystal with 12 MHz frequency or less¾We can observe the frequency on the XTAL2 pin using the oscilloscope

P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7RST(RXD)P3.0(TXD)P3.1(INT0)P3.2(INT1)P3.3(T0)P3.4(T1)P3.5(WR)P3.6(RD)P3.7XTAL2XTAL1GND

VccP0.0(AD0)P0.1(AD1)P0.2(AD2)P0.3(AD3)P0.4(AD4)P0.5(AD5)P0.6(AD6)P0.7(AD7)-EA/VPPALE/PROG-PSENP2.7(A15)P2.6(A14)P2.5(A13)P2.4(A12)P2.3(A11)P2.2(A10)P2.1(A9)P2.0(A8)

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(^40393837363534333280513130) (8031) 292827262524232221