16
Type
Symbol
I/O
Name and Function
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: Selection signal for areas 0 to 7.
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/write enable/upper write enable:
A strobe signal that writes to external space and
indicates that the upper half (D15 to D8) of the data
bus is enabled.
The 2CAS type DRAM write enable signal.
The 2WE type DRAM upper write enable signal.
LWR
Output
Low write/lower column address strobe/lower write
enable:
A strobe signal that writes to external space and
indicates that the lower half (D7 to D0) of the data bus
is enabled.
The 2CAS type (LCASS = 1) DRAM lower column
address strobe signal.
The 2WE type DRAM lower write enable signal.
CAS
Output
Upper column address strobe/column address strobe:
The 2CAS type DRAM upper column address strobe
signal.
LCAS
Output
Lower column address strobe:
The 2CAS type DRAM lower column address strobe
signal.
OE
Output
Output enable:
Output enable signal for DRAM space read access.
WAIT
Input
Wait: Requests insertion of a wait state in the bus
cycle when accessing external 3-state address space.
Содержание H8S/2631
Страница 28: ...xviii Appendix G Package Dimensions 1154 ...
Страница 341: ...316 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 9 8 Memory Mapping in Block Transfer Mode ...
Страница 918: ...905 ø DREQ0 DREQ1 tDRQS tDRQH Figure 25 19 DMAC DREQ Input Timing ...
Страница 955: ...943 A 2 Instruction Codes Table A 2 shows the instruction codes ...