Table of Contents
Advertisement
(3)
Address, bus width, space mode to use, and address space setting
ＳＷ３
Name
Bus width 16 bits/8
Sets the bus access from the CPU board.
bits
(Set according to the CPU board to use)
(SW1-8)
Sets the access mode to G9001A.
Space mode to use
512-byte access setting
512-byte mode
(Space: 1024 bytes in total)
/ 8-byte mode
8-byte access setting
(SW1-7)
(Space: 32 bytes in total)
Address space
Switches between memory access and I/O access for the board.
MEM / IO
(MEM: Memory mapped I/O access / I/O: I/O mapped I/O access)
(SW1-6)
* "MEM" setting is disabled when bus width is set to 8 bits.
ALE signal ON/OFF
Selects whether or not to latch the address using ALE.
(SW1-5)
(Note that some CPU board may not be able to output ALE signal.)
A9 - A5
Address
A15 - A10
Address
A19 - A16
Address
A23 - A20
Address
Figure 2.3-5 Address, bus width, space mode to use, and address space setting switch
(4)
Setting examples of address, bus width, space mode to use, and address space
Setting example of I/O mapped I/O access (Default setting)
・ Address
・ ALE signal
・ Address space
・ Space mode to use : 8-byte mode
(Space actually used: 32-byte space)
・ Bus width
ＳＷ３
ＳＷ２
Figure 2.3-6 Setting example of I/O mapped and memory mapped I/O access
ＳＷ２
A9-A5 (Valid only with 8-byte access)
A15-A10
A19-A16 (Valid only with memory mapped I/O)
A23-A20 (Valid only with memory mapped I/O)
: '000980H'
: Unused
: I/O mapped I/O access)
: 8 bits
ＳＷ１
ＳＷ１
Function
Normally used setting.
Appropriate when there are few
CPU board resources.
Setting example of memory mapped I/O access
・ Address
・ ALE signal
・ Address space
・ Space mode to use : 512-byte mode
(Space actually used: 1024-byte space)
・ Bus width
ＳＷ３
29
ON
16 bits
8 bits
512-byte
8-byte
mode
mode
Memory
Enabled
Disabled
1
1
1
1
: '0D8000H'
: Unused
: Memory mapped I/O access
: 16 bits
ＳＷ２
ＳＷ１
OFF
I/O
0
0
0
0
Advertisement
Table of Contents
