Fujitsu FR81S User Manual
CHAPTER 36: EXTERNAL BUS INTERFACE
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : EXTERNAL BUS INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
48
• CS2 settings
To allocate the space from 0x00110000 to 1MByte:
Set ASZ[3:0]=0100 to allocate a space of 1MByte. At that time, the SADR enable bit is [31:20].
SADR[19:16] is not the target of the comparison with the address. Therefore, the starting address of the
CS2 area is 0x00100000 rather than 0x00110000.
ASR2:ASZ[3:0]=0100
ASR2:SADR[31:16]=0x0010
→ 0x00100000 to 0x001FFFFF becomes the CS2 area.
• CS3 settings
ASR3:ASZ[3:0]=0010
ASR3:SADR[31:16]=0x0FFC
→ 0x0FFC0000 to 0x0FFFFFFF becomes the CS3 area.
Figure 5-11 Setting Example
Reading and comparing ASR
After configuring the required ACR, AWR, and ASR settings for a CS, read the ASR which was configured
last and compare to the set value in order to ensure that the CS settings will apply to subsequent accesses.
CS settings and update sample program
This section shows a CS configuration sample program that configures CS1.
Initial state
0x00000000
0x7FFFFFFF
0xFFFFFFFF
Setting example
0x00000000
0x00200000
0x00100000
0x000C0000
0x00070000
0x00060000
0x10000000
0x0FFC0000
0x7FFFFFFF
0xFFFFFFFF
256Kbyte
256Kbyte
64Kbyte
1Mbyte
CS0 area
CS2 area
CS1 area
CS0 area
CS3 area
MB91520 Series
MN705-00010-1v0-E
1247