W79E825A Datasheet, PDF (93/127 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E825A/824A/823B/822B Data Sheet
20.3 Push-Pull Output Configuration
The push-pull output mode has two strong pull-up and pull-down structure that support large source
and sink current output. It removes “weak” pull-up and “very weak” pull-up resister and remain “strong
pull-up resister on quasi-bidirectional output mode. The “strong” pull-up is always turns on when port
latch is logic “1” to support source current. The push-pull port configuration is shown in below Figure.
The W79E825 series have three port pins that can’t be configured. They are P1.2, P1.3, and P1.5.
The port pins P1.2 and P1.3 are configured to open drain outputs. They may be used as inputs by
writing ones to their respective port latches.
Port Latch
Data
Input Data
VDD
P
N
Port Pin
Figure 20-4: Push-Pull Output
20.4 Input Only Configuration
By configure this mode, the ports are only digital input and disable digital output. The W79E825 series
can select input pin to Schmitt trigger or TTL level input by PxM1.y and PxM2.y registers.
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Publication Release Date: February 21, 2008
Revision A9