The addresses for the page register are as follows:
Page Register
DMA Channel 0
DMA Channel 1
DMA Channel 2
DMA Channel 3
DMA Channel 5
DMA Channel 6
DMA Channel 7
Refresh
Table 6-6: I/O Hex Address
I/O Hex Address
0087
0083
0081
0082
0088
0089
008A
008F
Address generation for the DMA channels is as follows:
Table 6-7: DMA Channel 3 Through 0
Note: To generate the addressing signal “byte high enable” (BHE),
invert address line AO.
Table 6-8: DMA Channels 7 Through 5
Note: The BHE and A0 addressing signals are forced to a logical 0.
DMA channel addresses do not increase or decrease through page
boundaries 64KB for channels 0 through 3 and 128KB for channels 5
through 7.
22
Chapter 6: Appendix
Summary of Contents for Apex 386SX/20
Page 1: ...PEER 2030 2 O M H z 3 8 6 S X S Y S T E M U ser s Manual ...
Page 15: ...Chapter 1 System Overview ...
Page 38: ...Chapter 2 Setting Up Your System ...
Page 43: ...Figure 2 2 The Location of W9 80386SX and 80387SX Chapter 2 Setting Up Your System 5 ...
Page 48: ...Figure 2 6 512KB Total Onboard System Memory 10 Chapter 2 Setting Up Your System ...
Page 49: ...Figure 2 7 640 KB Total Onboard System Memory Chapter 2 Setting Up Your System 11 ...
Page 50: ...Figure 2 8 1 MB Total Onboard System Memory 12 Chapter 2 Setting Up Your System ...
Page 51: ...Figure 2 9 1 5 MB Total Onboard System Memory Chapter 2 Setting Up Your System 13 ...
Page 52: ...Figure 2 11 2MB Total Onboard System Memory B 14 Chapter 2 Setting Up Your System ...
Page 53: ...Figure 2 12 3MB Total Onboard System Memory Chapter 2 Setting Up Your System 15 ...
Page 54: ...Figure 2 13 4MB Total Onboard System Memory 16 Chapter 2 Setting Up Your System ...
Page 55: ...Figure 2 14 5MB Total Onboard System Memory Chapter 2 Setting Up Your System 17 ...
Page 61: ...Chapter 3 Operating Your System ...
Page 80: ...Chapter 4 Keyboard ...
Page 90: ...Chapter 5 Troubleshooting ...
Page 98: ...Appendix ...
Page 123: ...Chapter 7 Glossary ...