HD6473258CP10 Datasheet, PDF (22/301 Pages) Renesas Technology Corp – Hitachi Single-Chip Microcomputer

(2) Pin Functions: Table 1-3 gives a concise description of the function of each pin.
Table 1-3. Pin Functions (1)
Type
Power
Symbol I/O
VCC
I
VSS
I
Clock XTAL I
EXTAL I
Ø
O
E
O
System RES
I
control STBY I
Address
bus
Data bus
Bus
control
A15 to A0 O
D7 to D0 I/O
WAIT I
RD
O
WR
O
AS
O
Name and function
Power: Connected to the power supply (+5 V or +3 V). Connect
both VCC pins to the system power supply (+5 V or +3 V).
Ground: Connected to ground (0 V). Connect both VSS pins to the
system power supply (0 V).
Crystal: Connected to a crystal oscillator. The crystal frequency
must be double the desired system clock frequency. If an external
clock is input at the EXTAL pin, a reverse-phase clock should be
input at the XTAL pin.
External crystal: Connected to a crystal oscillator or external
clock. The frequency of the external clock must be double the
desired system clock frequency. See section 14, Clock Pulse
Generator for examples of connections to a crystal and external
clock.
System clock: Supplies the system clock to peripheral devices.
Enable clock: Supplies an E clock to peripheral devices.
Reset: A low input causes the chip to reset.
Standby: A transition to the hardware standby mode
(a power-down state) occurs when a low input is received at the
STBY pin.
Address bus: Address output pins.
Data bus: 8-Bit bidirectional data bus.
Wait: Requests the CPU to insert TW states into the bus cycle
when an off-chip address is accessed.
Read: Goes low to indicate that the CPU is reading an external
address.
Write: Goes low to indicate that the CPU is writing to an external
address.
Address Strobe: Goes low to indicate that there is a valid address
on the address bus.
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