Epson S1C33L03 Benutzerhandbuch
II CORE BLOCK: BCU (Bus Control Unit)
B-II-4-14
EPSON
S1C33L03 FUNCTION PART
For information on memory connection, see Figure 4.18.
Byte 1
15
Data bus
0
#WRL
0
0
#WRH
0
0
A0
0
0
A1
0
1
No.
1
2
2
Byte 0
Byte 3
Byte 2
Byte 3
Byte 2
Byte 1
Byte 0
31
0
A[1:0]=10
A[1:0]=00
15
0
1
2
15
0
Source (general-purpose register)
Destination (16-bit device)
Bus operation
Little-endian
Byte 3
15
Data bus
0
#WRL
0
0
#WRH
0
0
A0
0
0
A1
0
1
No.
1
2
2
Byte 2
Byte 1
Byte 0
Byte 3
Byte 2
Byte 1
Byte 0
31
0
A[1:0]=00
A[1:0]=10
15
0
2
1
15
0
Source (general-purpose register)
Destination (16-bit device)
Bus operation
Big-endian
Figure 4.5 Word Data Writing to a 16-bit Device
Byte 1
15
Data bus
0
#WRL
1
1
#WRH
1
1
A0
0
0
A1
0
1
No.
1
2
2
Byte 0
Byte 3
Byte 2
Bus operation
1
2
Byte 3
Byte 2
Byte 1
Byte 0
31
0
Destination (general-purpose register)
A[1:0]=10
A[1:0]=00
Source (16-bit device)
15
0
15
0
Little-endian
Byte 3
15
Data bus
0
#WRL
1
1
#WRH
1
1
A0
0
0
A1
0
1
No.
1
2
2
Byte 2
Byte 1
Byte 0
Bus operation
2
1
Byte 3
Byte 2
Byte 1
Byte 0
31
0
Destination (general-purpose register)
A[1:0]=00
A[1:0]=10
Source (16-bit device)
15
0
15
0
Big-endian
Figure 4.6 Word Data Reading from a 16-bit Device
Byte 1
15
Data bus
0
#WRL
0
#WRH
0
A0
0
A1
∗
No.
1
Byte 0
Byte 3
Byte 2
Byte 1
Byte 0
31
0
A[1:0]=
∗
0
0
1
15
Source (general-purpose register)
Destination (16-bit device)
Bus operation
Little-endian
Byte 1
15
Data bus
0
#WRL
0
#WRH
0
A0
0
A1
∗
No.
1
Byte 0
Byte 3
Byte 2
Byte 1
Byte 0
31
0
A[1:0]=
∗
0
0
1
15
Source (general-purpose register)
Destination (16-bit device)
Bus operation
Big-endian
Figure 4.7 Half-word Data Writing to a 16-bit Device
Byte 1
15
Data bus
0
#WRL
1
#WRH
1
A0
0
A1
∗
No.
1
Byte 0
Bus operation
1
Sign or Zero extension
Byte 1
Byte 0
31
0
Destination (general-purpose register)
A[1:0]=
∗
0
Source (16-bit device)
0
15
Little-endian
Byte 1
15
Data bus
0
#WRL
1
#WRH
1
A0
0
A1
∗
No.
1
Byte 0
Bus operation
1
Sign or Zero extension
Byte 1
Byte 0
31
0
Destination (general-purpose register)
A[1:0]=
∗
0
Source (16-bit device)
0
15
Big-endian
Figure 4.8 Half-word Data Reading from a 16-bit Device