CHAPTER 2 PIN FUNCTIONS
(6) P70 to P77 (port 7) ... Input
Port 7 is an 8-bit input-only port in which all the pins are fixed to input.
In addition to functioning as input ports pins, P70 to P77 can also be used for A/D converter (ADC) analog
input in the control mode.
Normally, when port and function pins are shared, their operation can be selected by the port mode control
register, but in the case of P70 to P77, such a register does not exist. Therefore, these pins cannot be
switched between input port and analog input pins for the A/D converter (ADC). For the state of each pin, read
the port.
(a) Port mode
P70 to P77 are input-only pins.
(b) Control mode (alternate function)
P70 to P77 are shared with ANI0 to ANI7, but switching is not possible.
(i) ANI0 to ANI7 (analog input) ... Input
These are the analog input pins to the A/D converter (ADC).
(7) P90 to P915 (port 9) ... I/O
Port 9 is a 16-bit I/O port for which input and output can be set in 1-bit units.
In addition to functioning as an I/O port, P90 to P915 can also be used for lower 16-bit address output within a
22-bit address on the address bus during external access in control mode 1, and for serial interface (UART1,
CSI01, CSIA1) I/O, 16-bit timer I/O, 8-bit timer output, and external interrupt request input in control mode 2.
Moreover, they can also function as 16-bit timer inputs, 8-bit timer inputs, and key interrupts in the input port
mode.
The port mode and control mode (alternate functions) can be selected as the operation mode for each bit, and
are specified by the port 9 mode control register (PMC9).
P90 to P915 can be set to control mode 1 or control mode 2 in 1-bit units by the port 9 function control register
(PFC9).
Normal output or N-ch open-drain output can be selected for P98, P99, P911, and P912.
(a) Port mode
P90 to P915 can be set to input or output in 1-bit units by the port 9 mode register (PM9) (when used as
the A0 to A15 pins, mode switching in 16-bit units is necessary).
(b) Control mode (alternate function)
P90 to P915 can be set to the port mode or control mode in 1-bit units by the port 9 mode control register
(PMC9).
(i) A0 to A15 (address bus) ... Output
These are the lower 16-bit address output pins within a 22-bit address on the address bus during
external access.
(ii) TXD1 (transmit data) ... Output
This is the serial transmit data output pin for UART1.
(iii) RXD1 (receive data) ... Input
This is the serial receive data input pin for UART1.
User’s Manual U15862EJ3V0UD
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NEC [ NEC ]
