MC96FM204/FM214
54
April 7, 2016 Ver. 1.8
9. I/O Ports
9.1 I/O Ports
The MC96FM204/FM214 has three groups of I/O ports (P0 ~ P2). Each port can be easily configured by
software as I/O pin, internal pull up and open-drain pin to meet various system configurations and design
requirements.
9.2 Port Register
9.2.1 Data Register (Px)
Data Register is a bidirectional I/O port. If ports are configured as output ports, data can be written to the
corresponding bit of the Px. If ports are configured as input ports, the data can be read from the corresponding bit
of the Px.
9.2.2 Direction Register (PxIO)
Each I/O pin can be independently used as an input or an output through the PxIO register. Bits cleared in this
register will make the corresponding pin of Px to input mode. Set bits of this register will make the pin to output
mode. Almost bits are cleared by a system reset, but some bits are set by a system reset.
9.2.3 Pull-up Resistor Selection Register (PxPU)
The on-chip pull-up resistor can be connected to I/O ports individually with a pull-up resistor selection register
(PxPU). The pull-up register selection controls the pull-up resister enable/disable of each port. When the
corresponding bit is 1, the pull-up resister of the pin is enabled. When 0, the pull-up resister is disabled. All bits
are cleared by a system reset.
9.2.4 Open-drain Selection Register (PxOD)
There are internally open-drain selection registers (PxOD) for P0, P1 and P2. The open-drain selection register
controls the open-drain enable/disable of each port. Almost ports become push-pull by a system reset, but some
ports become open-drain by a system reset.
9.2.5 Debounce Enable Register (PxDB)
P00, P10, P11, P13, P14, and P15 support debounce function. Debounce clocks of each ports are fx/1, fx/4,
and fx/4096.
9.2.6 Port Function Selection Register (PxFSR)
These registers define alternative functions of ports. Please remember that these registers should be set
properly for alternative port function. A reset clears the PxFSR register to
‘00H’, which makes all pins to normal
I/O ports.
Summary of Contents for MC96FM204
Page 17: ...MC96FM204 FM214 April 7 2016 Ver 1 8 17 4 Package Diagram Figure 4 1 20 Pin SOP Package ...
Page 18: ...MC96FM204 FM214 18 April 7 2016 Ver 1 8 Figure 4 2 20 Pin TSSOP Package ...
Page 19: ...MC96FM204 FM214 April 7 2016 Ver 1 8 19 Figure 4 3 16 Pin SOP Package ...
Page 20: ...MC96FM204 FM214 20 April 7 2016 Ver 1 8 Figure 4 4 16 Pin TSSOP Package ...
