HD6412340 HITACHI [Hitachi Semiconductor], HD6412340 Datasheet - Page 169

• Manufacturer Part Number: HD6412340
• Description: H8S/2345 F-ZTAT Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

6.4.3
Table 6.4 shows the data buses used and valid strobes for the access spaces.
In a read, the RD signal is valid without discrimination between the upper and lower halves of the
data bus.
In a write, the HWR signal is valid for the upper half of the data bus, and the LWR signal for the
lower half.
Table 6.4
Area
8-bit access
space
16-bit access Byte
space
Note: Hi-Z: High impedance.
150
Invalid: Input state; input value is ignored.
Valid Strobes
Data Buses Used and Valid Strobes
Access
Size
Byte
Word
Read/
Write
Read
Write
Read
Write
Read
Write
Address
—
—
Even
Odd
Even
Odd
—
—
Valid
Strobe
RD
HWR
RD
HWR
LWR
RD
HWR, LWR Valid
Upper Data Bus
(D
Valid
Valid
Invalid
Valid
Hi-Z
Valid
15
to D
8
)
Lower data bus
(D
Invalid
Hi-Z
Invalid
Valid
Hi-Z
Valid
Valid
Valid
7
to D
0
)