AUTOMOTIVE MICROCONTROLLER MCS 51
270499 –2
Resident in 8052 8032 only
Figure 2 MCS 51 Microcontroller Block Diagram
PIN DESCRIPTIONS
V
CC
Supply voltage
Port 0 pins that have 1s written to them float and in
that state can be used as high-impedance inputs
Port 0 is also the multiplexed low-order address and
data bus during accesses to external Program and
Data Memory In this application it uses strong inter-
nal pullups when emitting 1s and can source and
sink 8 LS TTL inputs
Port 0 also outputs the code bytes during program
verification of the ROM External pullups are re-
quired
V
SS
Circuit ground
Port 0
Port 0 is an 8-bit open drain bidirectional I O port As
an output port each pin can sink 8 LS TTL inputs
3
INTEL [ INTEL CORPORATION ]
