Philips 8-bit microcontroller with two-clock 80C51 core UM10109 Manual De Usuario
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 02 — 23 May 2005
30 of 133
Philips Semiconductors
UM10109
P89LPC932A1 User manual
4.4 Input-only configuration
The input port configuration is shown in
. It is a Schmitt-triggered input that also
has a glitch suppression circuit.
(Please refer to the P89LPC932A1 data sheet, Dynamic characteristics for glitch filter
specifications).
specifications).
4.5 Push-pull output configuration
The push-pull output configuration has the same pull-down 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.
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
.
A push-pull port pin has a Schmitt-triggered input that also has a glitch suppression
circuit.
circuit.
(Please refer to the P89LPC932A1 data sheet, Dynamic characteristics for glitch filter
specifications).
specifications).
Fig 11. Input only.
002aaa916
input
data
PORT
PIN
glitch rejection
Fig 12. Push-pull output.
002aaa917
port latch
data
input
data
PORT
PIN
strong
glitch rejection
V
DD
P
N