Epson S1C33210 Technical Manual page 165

These bus operations are shown in the figure below, taking the example of the A0 method.
With the BSL method, the following adjustments should be made when reading the figure.
(1) For data reads, the operation is as shown in the figure below.
(2) For little-endian data writes, read A0 as #BSC, and #WRH as #BSH.
(3) For big-endian data writes, read A0 as #BSL, and #WRL as #BSH.
For information on memory connection, see Figure 4.18.
Little-endian
Source (general-purpose register)
31
Byte 3 Byte 2
2
15
A[1:0]=10
Destination (16-bit device)
Big-endian
Source (general-purpose register)
31
Byte 3 Byte 2
1
15
A[1:0]=00
Destination (16-bit device)
Little-endian
Destination (general-purpose register)
31
Byte 3 Byte 2
2
15
A[1:0]=10
Source (16-bit device)
Big-endian
Destination (general-purpose register)
31
Byte 3 Byte 2
1
15
A[1:0]=00
Source (16-bit device)
Little-endian
Source (general-purpose register)
31
Byte 3 Byte 2
Big-endian
Source (general-purpose register)
31
Byte 3 Byte 2
S1C33210 FUNCTION PART
Byte 1 Byte 0
1
0 15
A[1:0]=00
Byte 1 Byte 0
2
0 15
A[1:0]=10
Figure 4.5 Word Data Writing to a 16-bit Device
Byte 1 Byte 0
1
0 15
A[1:0]=00
Byte 1 Byte 0
2
0 15
A[1:0]=10
Figure 4.6 Word Data Reading from a 16-bit Device
Byte 1 Byte 0
1
15
A[1:0]= 0
Destination (16-bit device)
Byte 1 Byte 0
1
15
A[1:0]= 0
Destination (16-bit device)
Figure 4.7 Half-word Data Writing to a 16-bit Device
II CORE BLOCK: BCU (Bus Control Unit)
0
No.
A1 A0 #WRH #WRL
1
0 0 0
0
2
1 0 0
0
No.
A1 A0 #WRH #WRL
1
0 0 0
0
2
1 0 0
0
No.
A1 A0 #WRH #WRL
1
0 0 1
0
2
1 0 1
0
No.
A1 A0 #WRH #WRL
1
0 0 1
0
2
1 0 1
0
No.
A1 A0 #WRH #WRL
1
0 0
0
0
No.
A1 A0 #WRH #WRL
1
0 0
0
EPSON
Bus operation
Data bus
15
Byte 1 Byte 0
0
Byte 3 Byte 2
0
Bus operation
Data bus
15
Byte 3 Byte 2
0
Byte 1 Byte 0
0
Bus operation
Data bus
15
Byte 1 Byte 0
1
Byte 3 Byte 2
1
Bus operation
Data bus
15
Byte 3 Byte 2
1
Byte 1 Byte 0
1
Bus operation
Data bus
15
Byte 1 Byte 0
0
Bus operation
Data bus
15
Byte 1 Byte 0
0
0
0
0
0
0
0
B-II-4-13