Hitachi H8S/2678 Series Reference Manual page 205

Port Description
Port D • 8-bit I/O
port
• Built-in
MOS input
pull-up
Port E • 8-bit I/O
port
• Built-in
MOS input
pull-up
Port F • 8-bit I/O
port
188
Pins
PD7/D15–PD0/D8
PE7/D7–PE0/D0
PF7/ø
PF6/AS
PF5/RD
PF4/HWR
PF3/LWR
PF2/LCAS/IRQ15
Modes Mode
1, 2, 5, 6
Data bus input/output
In 8-bit bus mode: I/O port
In 16-bit bus mode: Data bus
input/output
When DDR = 1 (after reset): ø
output
When DDR = 0: Input port
When ASOE = 1 (after reset):
AS output
When ASOE = 0: I/O port
RD, HWR output
When LWROE = 1 (after reset):
LWR output
When LWROE = 0: I/O port
When areas 2 to 5 are all
normal space (after reset), or
when DRAM space areas are
all in 8-bit bus mode: I/O port
also functioning as IRQ15
interrupt input
When any DRAM space is in
16-bit bus mode: Dual function
as IRQ15 interrupt input and
LCAS output
4
When EXPE = 0 (after reset):
I/O port
When EXPE = 1: Data bus
input/output
When EXPE = 0 (after reset):
I/O port
When EXPE = 1 in 8-bit bus
mode: I/O port
When EXPE = 1 in 16-bit bus
mode: Data bus input/output
When DDR = 0: Input port (after
reset)
When DDR = 1: ø output
When EXPE = 0 (after reset), or
when EXPE = 1 and ASOE = 0:
I/O port
When EXPE = 1 and ASOE = 1:
AS output
When EXPE = 0 (after reset):
I/O port
When EXPE = 1: RD, HWR
output
When EXPE = 0 (after reset), or
when EXPE = 1 and LWROE =
0: I/O port
When EXPE = 1 and LWROE =
1: LWR output
When EXPE = 0 (after reset), or
when EXPE = 1 and areas 2 to
5 are all normal space, or when
EXPE = 1 and DRAM space
areas are all in 8-bit bus mode:
I/O port also functioning as
IRQ15 interrupt input
When EXPE = 1 and any
DRAM space is in 16-bit bus
mode: Dual function as IRQ15
interrupt input and LCAS output
Mode
7