EZ80F91MCU ZILOG [Zilog, Inc.], EZ80F91MCU Datasheet - Page 78

• Manufacturer Part Number: EZ80F91MCU
• Description: eZ80Acclaim-TM Flash Microcontrollers
• Manufacturer: ZILOG [Zilog, Inc.]

Table 6. GPIO Mode Selection
PS019209-0504
GPIO
Mode
1
2
3
4
5
6
7
8
9
Px_ALT2
Bits7:0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
GPIO Mode 1.
value written to the Port x Data register (Px_DR) is presented on the pin.
GPIO Mode 2.
is tristated (high impedance). The value stored in the Port x Data register pro-
duces no effect. As in all modes, a Read from the Port x Data register returns the
pin’s value. GPIO Mode 2 is the default operating mode following a RESET.
GPIO Mode 3.
feature an internal pull-up to the supply voltage. To employ the GPIO pin in
OPEN-DRAIN mode, an external pull-up resistor must connect the pin to the sup-
ply voltage. Writing a 0 to the Port x Data register outputs a Low at the pin. Writing
a 1 to the Port x Data register results in high-impedance output.
GPIO Mode 4.
not feature an internal pull-down to the supply ground. To employ the GPIO pin in
OPEN-SOURCE mode, an external pull-down resistor must connect the pin to the
Px_ALT1
Bits7:0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
The port pin is configured as open-source I/O. The GPIO pins do
The port pin is configured as a standard digital output pin. The
The port pin is configured as a standard digital input pin. The output
The port pin is configured as open-drain I/O. The GPIO pins do not
Px_DDR
Bits7:0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bits7:0 Port Mode
Px_DR
P R E L I M I N A R Y
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Output
Output
Input from pin
Input from pin
Open-drain output
Open-drain I/O
Open-source I/O
Open-source output
Reserved
Interrupt—dual edge-triggered
Port B, C, or D—alternate function controls port I/O.
Port B, C, or D—alternate function controls port I/O.
Interrupt—active Low
Interrupt—active High
Interrupt—falling edge-triggered High impedance
Interrupt—rising edge-triggered High impedance
General-Purpose Input/Output
Product Specification
Output
0
1
High impedance
High impedance
0
High impedance
High impedance
1
High impedance
High impedance
High impedance
High impedance
eZ80F91 MCU
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