Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

PIN HANEL

DESCRIPTION

EA

‰EA, “external access’’, is an input pin and must be connected to Vcc or GND

¾The 8051 family members all come with on-chip ROM to store programs

ƒ-EA pin is connected to Vcc

¾The 8031 and 8032 family members do no have on-chip ROM, so code is stored on an external ROM and is fetched by 8031/32

ƒ-EA pin must be connected to GND to indicate that the code is stored externally

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)

(^1234567891011121314151617181920)
(^40393837363534333280513130) (8031) 292827262524232221