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CHAPTER 2 PIN FUNCTIONS
(4) P30 to P37 (Port 3) ... 3-state I/O
These pins constitute an 8-bit I/O port, port 3. They also function as control signal pins. P30 to P37 function
not only as I/O port pins but also as input/output for RPU, external interrupt request, and serial interface (CSI3)
I/O pins in the control mode.
(a) Port mode
P30 to P37 can be set in the input or output mode in 1-bit units by port 3 mode register (PM3).
(b) Control mode
P30 to P37 can be set in the port or control mode in 1-bit units by the PMC3 register.
(i)
TO130, TO131 (Timer Output) ... output
These pins output pulse signals from timer 1.
(ii)
TCLR13 (Timer Clear) ... input
This pin inputs an external clear signal to timer 1.
(iii) TI13 (Timer Input) ... input
This pin inputs an external count clock to timer 1.
(iv) INTP130 to INTP133 (Interrupt Request from Peripherals) ... input
These pins are the external interrupt request input pins of timer 1.
(v)
SO3 (Serial Output 3) ... output
This pin outputs the serial transmit data of CSI.
(vi) SI3 (Serial Input 3) ... input
This pin inputs the serial receive data of CSI.
(vii) SCK3 (Serial Clock 3) ... 3-state I/O
This pin inputs/outputs the serial clock of CSI.
(5) P40 to P47 (Port 4) ... 3-state I/O
These pins constitute an 8-bit I/O port, port 4. They also form a portion of the address/data bus connected
to external memory.
P40 to P47 function not only as I/O port pins but also as multiplexed address/data bus pins (AD0 to AD7) in
the control mode (external expansion mode) when an external memory is connected.
Each bit of this port can be set in the port or control mode, in 1-bit units, by using the mode specification pin
(MODE) and the memory expansion mode register (MM).
(a) Port mode
P40 to P47 can be set in the input or output port mode in 1-bit units by using port 4 mode register (PM4).
(b) Control mode (External Expansion Mode)
P40 to P47 can be specified as AD0 to AD7 by using the MODE pin and MM register.