Lattice Semiconductor ispLever Core Multi-Channel DMA Controller, User Manual, Page: 22 / 29

Lattice Semiconductor Multi-Channel DMA Controller User’s Guide
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Table 15. Channel Control Register – Non-8237 Mode
Register Address Map
The 8237 and non-8237 modes of the MCDMA Controller decode and use different numbers of
ain
bit input sig-
nals. The
ain
signal is used for mapping the register address and decoding software command.
Table 16. Register Address Map and Software Command of 8237 Mode
In the 8237 mode, the additional software commands are: Clear Byte Pointer, Master Clear and Clear Mask Regis-
ter.
Table 17. Register Address Map and Software Command of Non-8237 Mode
Bit Description
0 0 Clear Request bit
1 Set Request bit
1 0 Channel unmasked
1 Channel masked
2 0 Auto Initialization disable
1 Auto Initialization enable
ain3 ain2 ain1 ain0 Channel
Write
iorin_n
= 1,
iowin_n
= 0
Read
iorin_n
= 0,
iowin_n
= 1
0 0 0 0
0
Base and current Address reg Current DMA address reg
0 0 0 1 Base and current Word Count reg Current Word Count reg
0 0 1 0
1
Base and current Address reg Current DMA address reg
0 0 1 1 Base and current Word Count reg Current Word Count reg
0 1 0 0
2
Base and current Address reg Current DMA address reg
0 1 0 1 Base and current Word Count reg Current Word Count reg
0 1 1 0
3
Base and current Address reg Current DMA address reg
0 1 1 1 Base and current Word Count reg Current Word Count reg
1 0 0 0 X Command Register Read Status Register
1 0 0 1 X Single Request bit command Illegal
1 0 1 0 X Single Mask bit command Illegal
1 0 1 1 X Mode Register Illegal
1 1 0 0 X Clear Byte Pointer command Illegal
1 1 0 1 X Master clear command Read temporary reg
1 1 1 0 X Clear Mask Register command Illegal
1 1 1 1 X Mask register Illegal
ain2 ain1 ain0
Write:
iorin_n
= 1,
iowin_n
= 0
Read:
iorin_n
= 0,
iowin_n
= 1
0 0 0 Command register
0 0 1 Source Address register
0 1 0 Word Count register
0 1 1 Destination Address register
1 0 0 Mode register
1 0 1 Channel Control register
1 1 0 Master Clear command
1 1 1 Clear Byte Pointer command