Valid Strobes (In Glueless Extension) - Renesas H8S Family Hardware Manual

Section 6 Bus Controller (BSC)
6.5.3

Valid Strobes (in Glueless Extension)

Table 6.14 shows the data buses used and valid strobes for each access space.
The RD and WR signals are valid for both the upper and lower halves of the data bus. In a write,
the HBE signal is valid for the upper half of the data bus, and the LBE signal for the lower half.
Table 6.14 Data Buses Used and Valid Strobes (Gluless Extension)
Access
Area Size
8-bit access
Byte
space
16-bit access
Byte
space
Word
[Legend]
Undefined: Undefined data is output.
Invalid: Input state with the input value ignored.
Ports or others: Used as ports or I/O pins for on-chip peripheral modules, and are not used as the
data bus.
Rev. 1.00 Mar. 12, 2008 Page 128 of 1178
REJ09B0403-0100
Read/
Write Address
Read —
Write —
Read Even
Odd
Write Even
Odd
Read —
Write —
Valid Upper Data Bus
Strobe (D15 to D8)
RD
Valid
WR
RD, HBE
Valid
RD, LBE
Invalid
WR, HBE
Valid
WR, LBE
Undefined
RD, HBE,
Valid
LBE
WR, HBE,
LBE
Lower Data
Bus (D7 to D0)
Ports or others
Invalid
Valid
Undefined
Valid
Valid