10 HITACHI
Table 1.3
Pin Functions (cont)
Type
Operating
mode
control
Symbol
MD2,
MD1,
MD0
Pin No.
79–77
I/O
I
Name and Function
Mode select: Selects the operating mode. Do not
change these inputs while the chip is operating. The
following table lists the possible operating modes and
their corresponding MD2–MD0 values.
MD2 MD1
0
0
0
0
1
1
1
1
MD0
0
1
0
1
0
1
0
1
Operating
Mode
MCU mode
On-chip
ROM
Bus
Size in
Area 0
8 bits
16 bits
0
0
1
1
0
0
1
1
Disabled
Enabled
*
1
(Reserved)
PROM
mode
*
2
Interrupts
NMI
74
I
Nonmaskable interrupt: Nonmaskable interrupt request
signal. The rising or falling edge can be selected for
signal detection.
Interrupt request 0–7: Maskable interrupt request
signals. Level input or edge-triggered input can be
selected.
Slave interrupt request output: Indicates occurrence of
an interrupt while the bus is released.
Address bus: Outputs addresses.
IRQ0
–
IRQ7
65–68,
97–100
I
IRQOUT
61
O
Address
bus
A21–A0
45–42, 40,
39, 37–33,
31–25,
23–20
19–16, 14,
12-5, 3–1
64
62
54
O
Data bus
AD15–
AD0
DPH
DPL
WAIT
I/O
Data bus: 16-bit bidirectional data bus that is
multiplexed with the lower 16 bits of the address bus.
Upper data bus parity: Parity data for D15–D8.
Lower data bus parity: Parity data for D7–D0.
Wait: Requests the insertion of wait states (T
W
) into
the bus cycle when the external address space is
accessed.
I/O
I/O
I
Bus
control
Notes :1.Use prohibited in the SH7020 Romless version.
2.Can only be used in the SH7021 ZTAT version.