Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 21 Port 4
FEUL620Q504 21-14
21.3 Description of Operation
21.3.1 Input/Output Port Functions
For each pin of Port 4, either output or input is selected by setting the Port 4 direction register (P4DIR).
In output mode, high-impedance output mode, P-channel open drain output mode, N-channel open drain output
mode, or CMOS output mode can be selected by setting the Port 4 control registers 0 and 1 (P4CON0 and
P4CON1).
In the input mode, set the port 4 control registers 0 and 1 (P4CON0 and P4CON1) to select any of
high-impedance input mode, input mode with a pull-down resistor, or input mode with a pull-up resistor.
At a system reset, high-impedance output mode is selected as the initial status.
In output mode, “L” or “H” level is output to each pin of Port 4 depending on the value set by the Port 4 data
register (P4D).
In input mode, the input level of each pin of Port 4 can be read from the Port 4 data register (P4D).
21.3.2 Primary Function Other Than Input/Output Port
The external interrupt input (EXI40 to EXI47) can be assigned to the port 4 as the primary function other than
the input/output port.
21.3.3 Secondary to Quartic Functions
The I2C bus pin (SDA0/1, SCL0/1), Melody/Buzzer output (MD0), low speed clock(LSCLKO), high speed
clock (OUTCLK), synchronous serial port pin (SIN0, SCK0, SOUT0), synchronous serial port with FIFO pin
(SINF0, SCKF0, SOUTF0, SSF0), UART pin (RXD0, TXD0), UART with FIFO pin (RXDF0, TXDF0), and
timer out output pin (TMOUT8/9/A/B) are assigned to the port 4 as the secondary, tertiary, or quartic function.
Each of them can be used as the secondary, tertiary or quartic function by setting the P47MD0 to P40MD0 and
P47MD1 to P40MD1 bits of the port 4 mode register (P4MOD0, P4MOD1).
Output frequency of High speed clock output can be selected by frequency control register 0 (FCON0) OUTC2
to OUTC0. See Chapter 6 “Clock Generation Circuit”.