HD6433308 Datasheet, PDF (93/349 Pages) Hitachi Semiconductor – Hitachi Single-Chip MicroComputer

the general-purpose input/output function, but in some cases both functions can operate
simultaneously. Table 5-1 summarizes the auxiliary functions of the ports.
Table 5-1. Auxiliary Functions of Input/Output Ports
I/O port
Port 1
Port 2
Port 3
Port 4
Port 5
Port 6
Port 7
Port 8
Port 9
Expanded modes
Address bus (Low)*¹
Address bus (High)*¹
Data bus*²
8-Bit and PWM timer input and output
Serial communication (asynchronous mode)
Free-running timer input/output, IRQ6 and IRQ7
Analog input
Serial communication (synchronous
mode)
E clock and IOS output
IRQ3 to IRQ5
Bus control and Ø output*²
IRQ0 to IRQ2 and ADTRG
Single-chip mode
—
—
Dual-port RAM data bus
Serial communication (synchronous
mode)
Dual-port RAM address select input
IRQ3 to IRQ5
Dual-port RAM interface control,
Ø output
IRQ0 to IRQ2 and ADTRG
Notes:
*1 Selected automatically in mode 1; software-selectable in mode 2
*2 Selected automatically in modes 1 and 2
5.2 Port 1
Port 1 is an 8-bit input/output port that also provides the low bits of the address bus. The function
of port 1 depends on the MCU mode as indicated in table 5-2.
Table 5-2. Functions of Port 1
Mode 1
Address bus (Low)
(A7 to A0)
Mode 2
Input port or
Address bus (Low)
(A7 to A0)*
Mode 3
Input/output port
* Depending on the bit settings in the data direction register: 0—input pin; 1—address pin
Pins of port 1 can drive a single TTL load and a 90pF capacitive load when they are used as
output pins. They can also drive light-emitting diodes and a Darlington pair. When they are
used as input pins, they have programmable MOS pull-ups.
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