HD6413003RVF RENESAS [Renesas Technology Corp], HD6413003RVF Datasheet - Page 130

• Manufacturer Part Number: HD6413003RVF
• Description: microcontroller (MCU)
• Manufacturer: RENESAS [Renesas Technology Corp]

6.3.3 Data Bus
The H8/3003 allows either 8-bit access or 16-bit access to be designated for each of areas 0 to 7.
An 8-bit-access area uses the upper data bus (D
data bus (D
In read access the RD signal applies without distinction to both the upper and lower data bus. In
write access the HWR signal applies to the upper data bus, and the LWR signal applies to the
lower data bus.
Table 6-4 indicates how the two parts of the data bus are used under different access conditions.
Table 6-4 Access Conditions and Data Bus Usage
Area
8-bit-access
area
16-bit-access
area
Note: Undetermined data means that unpredictable data is output.
Invalid means that the bus is in the input state and the input is ignored.
15
to D
Access Read/
Size
—
Byte
Word
8
) and lower data bus (D
Write
Read
Write
Read
Write
Read
Write
Address Strobe
—
—
Even
Odd
Even
Odd
—
—
7
to D
Valid
RD
HWR
RD
HWR
LWR
RD
HWR, LWR Valid
15
112
0
).
to D
8
). A 16-bit-access area uses both the upper
Upper Data Bus
(D
Valid
Valid
Invalid
Valid
Undetermined data Valid
Valid
15
to D
8
)
Lower Data Bus
(D
Invalid
Undetermined data
Invalid
Valid
Undetermined data
Valid
Valid
7
to D
0
)