HD6413308 Hitachi Semiconductor, HD6413308 Datasheet - Page 95

• Manufacturer Part Number: HD6413308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: Hitachi Semiconductor

Mode 1: In mode 1 (expanded mode without on-chip ROM), port 1 is automatically used for
address output. The port 1 data direction register is unwritable. All bits in P1DDR 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 1 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 1 is a general-purpose input/output port.
Reset: A reset clears P1DDR and P1DR to all “0,” placing all pins in the input state with the MOS
pull-ups off. In mode 1, when the chip comes out of reset, P1DDR is set to all "1."
Hardware Standby Mode: All pins are placed in the high-impedance state with the MOS pull-ups
off.
Software Standby Mode: In the software standby mode, both P1DDR and P1DR remain in their
previous state. Address output pins are Low. General-purpose output pins continue to output the
data in P1DR.
Figure 5-1 shows a schematic diagram of port 1.
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