Fujitsu F2MC-8FX Hardware Manual page 122

CHAPTER 9 I/O PORT
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.
However, if the peripheral function input is enabled for the interrupt pin selection circuits (INT07 to
INT00), the input is enabled and not blocked.
• 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 of the external interrupt input pin
• Set the DDR register bit, which is corresponding to the external interrupt input pin, to "0".
• For other peripheral functions sharing pins, disable its output.
• Pin values are continuously input to the external interrupt circuit. When using the pin for a function
other than an interrupt, you must disable the corresponding external interrupt.
Operation as an analog input
• Set the DDR bit, which is corresponding to the analog input pin, to "0", and set the AIDRL bit to "0".
• For other peripheral functions sharing pins, disable its output.
Also, write also the corresponding PUL bit to "0".
Operation as LCDC segment output
• Set the DDR register bit, which is corresponding to the LCDC segment output pin, to "0".
• For other peripheral functions sharing pins, disable its output.
• Select the common/segment pin in LCDC enable registers (LCDCE1 to 6), and then set the port input
control bit (PICTL) in LCDC enable register (LCDCE1) to "1".
Behavior of the pull-up register
• Writing "1" to the PUL internally connects the pull-up register to the pin. When the output is "L" level,
the pull-up register is disconnected regardless of the PUL value.
Table 9.2-4 shows the pin states of the port.
Table 9.2-4 Pin State of Port 0
Normal operation
Operating Sleep
state Stop (SPL=0)
Watch (SPL=0)
I/O port/
Pin state
peripheral function I/O
SPL: Pin state specification bit in standby control register (STBC:SPL)
Hi-Z: High impedance
*: "Input enabled" means that the input function is enabled; it requires the pull-up or pull-down operation, or preventing
leaks by external inputs. Same as other ports when used as an output port.
108
Stop (SPL=1)
Watch (SPL=1)
Hi-Z
(Note, however, that pull-up setting
is in effect)
Input cutoff
(If external interrupts are enabled,
the external interrupt can be input.)
At reset
Hi-Z
Input enabled* (Not functional)