HD6413308 Hitachi Semiconductor, HD6413308 Datasheet - Page 31

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

Table 1-3. Pin Functions (2)
Type
Data bus
Bus
control
Interrupt
signals
Operating MD
mode
control
Symbol
D
WAIT
RD
WR
AS
IOS
NMI
IRQ
IRQ
MD
7
to D
1
0
0
7
,
to
0
I/O
I/O
I
O
O
O
O
I
I
I
Name and function
Data bus: 8-Bit bidirectional data bus.
Wait: Requests the CPU to insert T
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.
I/O Select: Goes Low when the CPU accesses addresses H’FF00
to H’FFFF. Can be used as a chip select signal replacing the upper
8 bits of the address bus when external devices are mapped onto
addresses H’FF80 to H’FF8F and H’FFA8 to H’FFAF.
NonMaskable Interrupt: Highest-priority interrupt request.
The NMIEG bit in the system control register determines whether
the interrupt is requested on the rising or falling edge of the NMI
input.
Interrupt Request 0 to 7: Maskable interrupt request pins.
Mode: Input pins for setting the MCU operating mode
according to the table below.
MD
0
1
1
The inputs at these pins are latched in mode select bits 1 to 0
(MDS1 and MDS0) of the mode register (MDCR) on the rising
edge of the RES signal.
1
MD
1
0
1
0
13
Mode
Mode 1
Mode 2
Mode 3
Description
Expanded mode with
Expanded mode with
Single-chip mode
on-chip ROM disabled
on-chip ROM enabled
W
states into the bus cycle