Datasheet

Section 6 Bus Controller (BSC)
Rev. 2.00 Sep. 28, 2009 Page 122 of 870
REJ09B0429-0200
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)
Area
Access
Size
Read/
Write
Address
Valid
Strobe
Upper Data Bus
(D15 to D8)
Lower Data
Bus (D7 to D0)
Read — RD
8-bit access
space
Byte
Write — WR
Valid Ports or others
Even RD, HBE Valid Invalid Read
Odd RD, LBE Invalid Valid
Even WR, HBE Valid Undefined
Byte
Write
Odd WR, LBE Undefined Valid
16-bit access
space
Word Read — RD, HBE,
LBE
Valid Valid
Write — WR, HBE,
LBE
[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.