
13
Type
Symbol
I/O
Name and Function
System control
STBY
Input
Standby: When this pin is driven low, a transition is made to
hardware standby mode.
BREQ
Input
Bus request: Used by an external bus master to issue a bus
request to the H8S/2214.
BACK
Output Bus request acknowledge: Indicates that the bus has been
released to an external bus master.
FWE
Input
Flash write enable Enables/disables flash memory
programming.
Interrupts
NMI
Input
Nonmaskable interrupt: Requests a nonmaskable interrupt.
When this pin is not used, it should be fixed high.
IRQ7 to
IRQ0
Input
Interrupt request 7 to 0: These pins request a maskable
interrupt.
Address bus
A23 to
A0
Output Address bus: These pins output an address.
Data bus
D15 to
D0
I/O
Data bus: These pins constitute a bidirectional data bus.
Bus control
CS7 to
CS0
Output Chip select: Signals for selecting areas 7 to 0.
AS
Output Address strobe: When this pin is low, it indicates that
address output on the address bus is enabled.
RD
Output Read: When this pin is low, it indicates that the external
address space can be read.
HWR
Output High write: A strobe signal that writes to external space and
indicates that the upper half (D15 to D8) of the data bus is
enabled.
LWR
Output Low write: A strobe signal that writes to external space and
indicates that the lower half (D7 to D0) of the data bus is
enabled.
WAIT
Input
Wait: Requests insertion of a wait state in the bus cycle
when accessing external 3-state address space.
External
expansion
EXIRQ7 to
EXIRQ0
Input
External expansion interrupt request 7 to 0: Input pins for
interrupt requests from external modules.
EXMS
Output External expansion module select: Select signal for external
modules.
EXDTC
Output External expansion DTC transfer end: DTC data transfer
end signal for
EXIRQ7 to EXIRQ0 input.
EXMSTP
Output External expansion module stop: Module stop signal for
external modules.