Port 2 Input Pull-Up Control Register (P2PCR)—H'FFAD
Bit
7
6
5
4
3
2
1
0
P2
7
PCR P2
6
PCR P2
5
PCR P2
4
PCR P2
3
PCR P2
2
PCR P2
1
PCR P2
0
PCR
Initial value
0
0
0
0
0
0
0
0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
P2PCR is an 8-bit readable/writable register that controls the input pull-up transistors in port 2. If a
bit in P2DDR is cleared to “0” (designating input) and the corresponding bit in P2PCR is set to “1,”
the input pull-up transistor for that bit is turned on.
Mode 1: In mode 1 (expanded mode without on-chip ROM), port 2 is automatically used for
address output. The port 2 data direction register is unwritable. All bits in P2DDR are
automatically set to “1” and cannot be cleared to “0.”
Mode 2: In mode 2 (expanded mode with on-chip ROM), the usage of port 2 can be selected on a
pin-by-pin basis. A pin is used for general-purpose input if its data direction bit is cleared to “0,”
or for address output if its data direction bit is set to “1.”
Mode 3: In the single-chip mode port 2 is a general-purpose input/output port.
Reset: A reset clears P2DDR, P2DR, and P2PCR to all “0,” placing all pins in the input state with
the pull-up transistors off. In mode 1, when the chip comes out of reset, P2DDR is set to all “1.”
Hardware Standby Mode: All pins are placed in the high-impedance state with the pull-up
transistors off. P2DR and P2PCR are initialized to H'00. In modes 2 and 3, P2DDR is initialized to
H'00.
Software Standby Mode: In the software standby mode, P2DDR, P2DR, and P2PCR remain in
their previous state. Address output pins are Low. General-purpose output pins continue to output
the data in P2DR.
Input Pull-Up Transistors: Port 2 has built-in programmable input pull-up transistors that are
available in modes 2 and 3. The pull-up for each bit can be turned on and off individually. To turn
on an input pull-up in mode 2 or 3, set the corresponding P2PCR bit to “1” and clear the
corresponding P2DDR bit to “0.” P2PCR is cleared to H'00 by a reset and in the hardware standby
mode, turning all input pull-ups off. In software standby mode, the previous state is maintained.
82
Summary of Contents for H8/326 Series
Page 67: ...58 ...
Page 121: ...112 ...
Page 274: ... 3 Clock Settling Timing Ø VCC RES STBY tOSC1 tOSC1 Figure 14 8 Clock Setting Timing 265 ...
Page 279: ...270 ...