HD643303x Hitachi, HD643303x Datasheet - Page 145

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

7.3.4 Input Pull-Up Transistors
Port 2 has built-in MOS input pull-up transistors that can be controlled by software. These input
pull-up transistors can be turned on and off individually.
When a P2PCR bit is set to 1 and the corresponding P2DDR bit is cleared to 0, the input pull-up
transistor is turned on.
The input pull-up transistors are turned off by a reset and in hardware standby mode. In software
standby mode they retain their previous state.
Table 7-4 summarizes the states of the input pull-up transistors in each mode.
Table 7-4 Input Pull-Up Transistor States (Port 2)
Mode
1
2
3
Legend
Off:
On/off: The input pull-up transistor is on if P2PCR = 1 and P2DDR = 0. Otherwise, it is off.
The input pull-up transistor is always off.
Reset
Off
Hardware Standby Mode
Off
130
Software Standby Mode
On/off
Other Modes
On/off