HD6475348R Datasheet, PDF (187/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

9.7.3 Pin Functions in Each Mode
The usage of port 6 depends on the MCU operating mode. Separate descriptions are given below.
Pin Functions in Mode 3: In mode 3 (the expanded maximum mode in which the on-chip ROM
is not used), P6DDR is automatically set for output, and the pins of port 6 carry the page address
bits (A19 – A16) of the address bus. Figure 9-16 shows the pin functions for mode 3.
A19 (output)
Port
A18 (output)
6
A17 (output)
A16 (output)
Figure 9-16 Port 6 Pin Functions in Mode 3
Pin Functions in Mode 4: In mode 4, (the expanded maximum mode in which the on-chip ROM
is used), software can select whether to use port 6 for general-purpose input, IRQ2 to IRQ5 input,
or output of page address bits.
If a bit in P6DDR is set to 1, the corresponding pin is used for page address output. If the P6DDR
bit is cleared to 0 and the corresponding IRQnE bit is cleared to 0, the pin is used for general-
purpose input. If the P6DDR bit is cleared to 0 and the corresponding IRQnE bit is set to 1, the
pin is used for IRQ2 to IRQ5 input. A reset initializes these pins to the general-purpose input
function, so when the address bus is used, all necessary bits in P6DDR must first be set to 1.
Figure 9-17 shows the pin functions in mode 4.
When P6DDR Bit
When P6DDR Bit is Cleared to 0
is Set to 1
IRQnE = 0
IRQnE = 1
A19 (output)
P63 (input)
IRQ5
Port
A18 (output)
P62 (input)
IRQ4
6
A17 (output)
P61 (input)
IRQ3
A16 (output)
P60 (input)
IRQ2
Figure 9-17 Port 6 Pin Functions in Mode 4
Pin Functions in Single-Chip Mode and Expanded Minimum Modes: In the single-chip mode
(mode 7) and expanded minimum modes (modes 1 and 2), the port 6 pins can be designated
individually as input or output pins.
Port 6 can be used for general-purpose input/output, IRQ input, or PWM output, depending on the
combination of settings of the IRQE and P6PWME bits in system control register 2 and the OE
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