h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 185

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

7.4.3
Table 7.4 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 7.4
Notes: Hi-Z: High impedance.
Area
8-bit access
space
16-bit access
space
Invalid: Input state; input value is ignored.
Valid Strobes
Data Buses Used and Valid Strobes
Access
Size
Byte
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
Rev. 5.00 Sep 22, 2005 page 159 of 1136
Upper Data Bus
(D15 to D8)
Valid
Valid
Invalid
Valid
Hi-Z
Valid
Valid
Section 7 Bus Controller
REJ09B0257-0500
Lower data bus
(D7 to D0)
Invalid
Hi-Z
Invalid
Valid
Hi-Z
Valid
Valid
Valid