Operations Of Port A - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 9 I/O PORT
9.8.2

Operations of Port A

This section describes the operations of port A.
Operations of Port A
Operation as an output port
• Setting the corresponding DDR bit to "1" sets a pin as an output port.
• For a peripheral function sharing pins, disable its output.
• When a pin is set as an output port, it outputs the value of the PDR to pins.
• If data is written to the PDR, the value is stored in the output latch and output to the pin as it is.
• Reading the PDR returns the PDR value.
Operation as an input port
• Setting the corresponding DDR bit to "0" sets a pin as an input port.
• For a peripheral function sharing pins, disable its output.
• When using the LCD shared pin as an input port, set the port input control bits (PICTL) in the LCDC
enable register (LCDCE1) to "1".
• If data is written to the PDR, the value is stored in the output latch but not output to the pin.
• Reading the PDR returns the pin value. However, the read-modify-write command returns the PDR
value.
Operation at reset
• Resetting the CPU initializes the DDR values to "0", and sets the port input enabled. Note that the pin
sharing for the LCD output is set its port input disabled since the port input control bit (PICTL) in
LCDC enable register (LCDCE1) is set to "0".
Operation in stop mode and watch mode
• If the pin state specification bit in the standby control register (STBC:SPL) is set to "1" when the device
switches to stop or watch mode, the pin is set forcibly to the high-impedance state regardless of the
DDR value. Note that the input is locked to "L" and blocked in order to prevent leaks due to freed input.
• If the pin state specification bit is "0", the state remains in port I/O or peripheral function I/O and the
output is maintained.
Operation as a LCDC common output
• Set the DDR register bit, which is corresponding to the LCDC common output pin, to "0".
• For other peripheral functions sharing pins, disable its output.
• Select the common/ment pin in LCDC enable registers (LCDCE1 to 6), and then set the port input
control bit (PICTL) in LCDC enable register (LCDCE1) to "1".
Operation of the input level selection register
• Writing "1" to the bit7 of ILSR2 changes Port A from the hysteresis input level to the automotive input
level. When the bit7 of ILSR2 is "0", it should be the hysteresis input level.
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