p87lpc778 NXP Semiconductors, p87lpc778 Datasheet - Page 36

• Manufacturer Part Number: p87lpc778
• Description: Cmos Single-chip 8-bit 80c51 Microcontroller 128-byte Data Ram, 8 Kb Otp
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 12378
Product data
8.9.3 Push-pull output configuration
The push-pull output configuration has the same pulldown structure as both the open
drain and the quasi-bidirectional output modes, but provides a continuous strong
pull-up when the port latch contains a logic 1. The push-pull mode may be used when
more source current is needed from a port output.
The push-pull port configuration is shown in
The three port pins that cannot be configured are P1.2, P1.3, and P1.5. The port pins
P1.2 and P1.3 are permanently configured as open drain outputs. They may be used
as inputs by writing ones to their respective port latches. P1.5 may be used as a
Schmitt trigger input if the P87LPC778 has been configured for an internal reset and
is not using the external reset input function RST.
Additionally, port pins P2.0 and P2.1 are disabled for both input and output if one of
the crystal oscillator options is chosen. Those options are described in
“Oscillator” on page
Fig 11. Open drain output.
Fig 12. Push-pull output.
port latch
Rev. 01 — 31 March 2004
data
39.
port latch
data
input
data
N
input
data
N
P
V DD
CMOS single-chip 8-bit microcontroller
Figure
12.
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
002aaa630
port
pin
P87LPC778
002aaa629
port
pin
Section 8.10
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