Intel MCS 51 User Manual page 112

i~. HARDWARE DESCRIPTION OF THE 8051,8052 AND 80C51
PO.O-PQ.7
P2.O-P2.7
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DRIVERS
w
Pom3
ORWERS
——————
XTAL1
—— ——— —,
X7AL2
'Rddenli. 805s/s0320mJy.
P
PORT3
LATCH
4&JJ
..
P3,0-P1.7
P3,0-P3.7
=
270252-1
Figure 1. MCS-51 Architectural Block Diagram
3-4