µPD75304B,75306B,75308B
5. PERIPHERAL HARDWARE FUNCTIONS
5.1 PORTS
There are four kinds of I/O ports, as follows.
• CMOS input (PORT0, 1)
: 8
• CMOS input/output (PORT2, 3, 6, 7) : 16
• N-ch open drain (PORT4, 5)
• CMOS output (BP0 to BP7)
:
:
8
8
Total
40
Fig. 5-1 Port Functions
Port (Symbol)
Function
Operation/Features
Remarks
Dual function as INT4, SCK, SO/
SB0 & SI/SB1 pins
PORT 0
PORT 1
PORT 2
PORT 7
PORT 3 *
PORT 6
Always readable or testable irrespective of
dual-function pin operating mode.
4-bit input
Dual function as pins INT0 to
INT2 & TI0
Dual function as PTO0, PCL &
BUZ pins
Can be set to input or output mode as 4-bit
unit. Ports 6 & 7 can be paired for 8-bit data
input/output.
Dual function as pins KR4 to
KR7
4-bit input/output
Dual function as LCDCL & SYNC
pins
Can be set to input or output mode bit-wise.
Dual function as pins KR0 to
KR3
4-bit input/output
(N-ch open-drain
10 V withstand
voltage)
Incorporation of pull-up resistor
can be specified bit-wise by
mask option.
Can be set to input or output mode as 4-bit
unit. Ports 4 & 5 can be paired for 8-bit data
input/output.
PORT 4 *
PORT 5 *
Outputs data bit-wise. Switchable by
software with LCD drive segment outputs
S24 to S31.
Small drive capability.
For CMOS load drive.
BP0 to BP7
1-bit output
*
Direct LED drive capability
21
NEC [ NEC ]
