NEC PD75402A - Manual (Page 53)

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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1.1 Digital Input/Output Port Types, Characteristics and Configuration
The different types of digital input/output ports are shown in Table 5-1, and the configuration of each port is shown
in Figs. 5-2, 5-3, 5-4 and 5-5.
Table 5-1 Digital Input/Output Port Types and Characteristics
Port
(Symbol)
Function
Can always be read or tested
regardless of dual-function pin
operating mode.
Can be set to input or output
mode bit by bit.
Can be set to input or output
mode as a 4-bit unit.
Can be set to input or output
mode as a 4-bit unit.
Operation/Characteristics Remarks
PORT0 4-bit input
PORT1
PORT3* 4-bit input/output
PORT2
PORT6*
PORT5* 4-bit input/ output
(N-ch open-drain,
up to 10 V)
Pins also function as SO/SB0, SI,
SCK, INT0, INT2. (See chapter 1.)
Port 2 pins also function as PCL.
Internal pull-up resistor can be
specified bit by bit by mask
option. (
µ
PD75402A only.)
* LED direct drive capability
On the
µ
PD75402A, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10. On the
µ
PD75P402, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10, and P50 through
P53 (see section 5.5).
P10 has a dual function as the external vectored interrupt input pin, and has an on-chip circuit for noise elimination
by the sampling clock (see section 6.2 for details).
Upon RESET input the output latches of ports 2, 3, 5 and 6 are cleared, the output buffer is turned off, and input
mode is set.