FM8P54/56
Rev1.21 May 31, 2005
P.10/FM8P54/56
FEELING
TECHNOLOGY
2.1.6 PORTA & PORTB (Port Data Registers)
Address
Name
05h (r/w)
PORTA
06h (r/w)
PORTB
Reading the port (PORTA, PORTB register) reads the status of the pins independent of the pin’s input/output modes.
Writing to these ports will write to the port data latch.
PORTA is a 4-bit port data Register. Only the low order 4 bits are used (PORTA<3:0>). Bits 7-4 are unimplemented
and read as ‘0’s.
PORTB is a 8-bit port data register.
2.1.7 PCON (Power Control Register)
Address
Name
B7
B6
B5
08h (r/w)
PCON
WDTE
EIS
LVDTE
Bit3:Bit0
: Not used. Read as “0”s.
ROC
: R-option function of IOA0 and IOA1 pins enable bit.
= 0, Disable the R-option function.
= 1, Enable the R-option function. In this case, if a 430K
external resister is connected/disconnected to Vss,
the status of IOA0 (IOA1) is read as “0”/”1”.
LVDTE
: LVDT (low voltage detector) enable bit.
= 0, Disable LVDT.
= 1, Enable LVDT.
EIS
: Define the function of IOB0/INT pin.
= 0, IOB0 (bi-directional I/O pin) is selected. The path of INT is masked.
= 1, INT (external interrupt pin) is selected. In this case, the I/O control bit of IOB0 must be set to “1”. The path
of Port B input change of IOB0 pin is masked by hardware, the status of INT pin can also be read by way
of reading PORTB.
WDTE
: WDT (watch-dog timer) enable bit.
= 0, Disable WDT.
= 1, Enable WDT.
2.1.8 WUCON (Port B Input Change Interrupt/Wake-up Control Register)
Address
Name
B7
B6
B5
09h (r/w)
WUCON
WUB7
WUB6
WUB5
WUB0
: = 0, Disable the input change interrupt/wake-up function of IOB0 pin.
= 1, Enable the input change interrupt/wake-up function of IOB0 pin.
WUB1
: = 0, Disable the input change interrupt/wake-up function of IOB1 pin.
= 1, Enable the input change interrupt/wake-up function of IOB1 pin.
WUB2
: = 0, Disable the input change interrupt/wake-up function of IOB2 pin.
= 1, Enable the input change interrupt/wake-up function of IOB2 pin.
WUB3
: = 0, Disable the input change interrupt/wake-up function of IOB3 pin.
= 1, Enable the input change interrupt/wake-up function of IOB3 pin.
B7
-
IOB7
B6
-
IOB6
B5
-
IOB5
B4
-
IOB4
B3
IOA3
IOB3
B2
IOA2
IOB2
B1
IOA1
IOB1
B0
IOA0
IOB0
B4
ROC
B3
-
B2
-
B1
-
B0
-
B4
B3
B2
B1
B0
WUB4
WUB3
WUB2
WUB1
WUB0