Section 22 PCI Controller (PCIC)
SH7751 Group, SH7751R Group
Page 966 of 1128
R01UH0457EJ0301 Rev. 3.01
Sep 24, 2013
22.4.5
Endian Control in Target Transfers (I/O Read/I/O Write)
The access size is fixed at longword when accessing the PCIC local register using I/O read or I/O
write commands. Addresses are specified using 4-byte boundaries, and
BE
[3:0] is specified as
B'0000.
The data alignment in target transfers (I/O read and I/O write) is shown in figure 22.22.
Size
LW
Address
4n
H'0000
PCI bus
B3 B2 B1 B0
31
0
BE
Local re
g
ister
B3 B2 B1 B0
31
0
Size
LW
Address
4n
H'0000
PCI bus
B3 B2 B1 B0
31
0
BE
Local re
g
ister
B3 B2 B1 B0
31
0
Target I/O read transfer data alignment (lo
c
al register
PCI bus)
Target I/O write transfer data alignment (PCI bus
lo
c
al register)
Figure 22.22 Data Alignment at Target I/O Transfer (Both Big Endian and Little Endian)
22.4.6
Endian Control in Target Transfers (Configuration Read/Configuration Write)
The data alignment when accessing the PCIC configuration register using the target configuration
read and configuration write commands is shown in figure 22.23.
In the SH7751 the access size is fixed at longword. The
BE
[3:0] value is ignored. In the SH7751R
all
BE
combinations are valid.