User manual
DIGITAL-LOGIC AG    MSM800SEV/SEL/BEV/XEV/XEL Detailed Manual V1.7 
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5.10.2.  System I/O Map
The following table details the legacy I/O range for 000h through 4FFh. Each I/O location has a read/write 
(R/W) capability. 
Note the following abbreviations: 
---  Unknown or cannot be determined. 
Yes  Read and write the register at the indicated location. No shadow required. 
WO  Write only. Value written can not be read back. Reads do not contain any useful information. 
RO  Read only. Writes have no effect. 
Shw 
The  value  written  to  the  register  can  not  be  read back via the  same  I/O  location.  Read back  is 
accomplished via a “Shadow” register located in MSR space. 
Shw@  Reads of the location return a constant or meaningless value. 
Shw$  Reads of the location return a status or some other meaningful information. 
Rec 
Writes  to  the  location  are  “recorded”  and  written  to  the  LPC.  Reads  to  the  location  return  the 
recorded value. The LPC is not read. 
I/O Map 
I/O Addr.
Function  Size
R/W  Comment 
000h  Slave DMA Address - Channel 0  8bit  Yes  16bit values in two transfers. 
001h  Slave DMA Counter - Channel 0  8bit  Yes  16bit values in two transfers. 
002h
Slave DMA Address - Channel 1  8bit  Yes  16bit values in two transfers. 
003h
Slave DMA Counter - Channel 1  8bit  Yes  16bit values in two transfers. 
004h
Slave DMA Address - Channel 2  8bit  Yes  16bit values in two transfers. 
005h
Slave DMA Counter - Channel 2  8bit  Yes  16bit values in two transfers. 
006h
Slave DMA Address - Channel 3  8bit  Yes  16bit values in two transfers. 
007h
Slave DMA Counter - Channel 3  8bit  Yes  16bit values in two transfers. 
008h
Slave DMA Command/Status - Channels [3:0]  8bit  Shw$
009h
Slave DMA Request - Channels [3:0]  8bit  WO  Reads return value B2h. 
00Ah
Slave DMA Mask - Channels [3:0]  8bit  Shw@
Reads return value B2h. 
00Bh
Slave DMA Mode - Channels [3:0]  8bit  Shw@
Reads return value B2h. 
00Ch
Slave DMA Clear Pointer - Channels [3:0]  8bit  WO  Reads return value B2h. 
00Dh
Slave DMA Reset - Channels [3:0]  8bit  WO  Reads return value B2h. 
00Eh
Slave DMA Reset Mask - Channels [3:0]  8bit  Shw@
Reads return value B2h. 
00Fh  Slave DMA General Mask - Channels [3:0]  8bit  Shw@
Reads return value B2h. 
010h-01Fh  No Specific Usage  ---  ---   
020h
PIC Master - Command/Status  8bit  Shw$
021h
PIC Master - Command/Status  8bit  Shw$
022h-03Fh  No Specific Usage  ---  ---   
040h
PIT – System Timer  8bit  Shw$
041h
PIT – Refresh Timer  8bit  Shw$
042h
PIT – Speaker Timer  8bit  Shw$
043h
PIT – Control  8bit  Shw$
044h-05Fh  No Specific Usage  ---  ---   
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