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AMD Geode™ SC3200 Processor Data Book 295
Core Logic Module - ISA Legacy Register Space
32581C
6.4.7 ISA Legacy Register Space
The ISA Legacy registers reside in the ISA I/O address
space in the address range from 000h to FFFh and are
accessed through typical input/output instructions (i.e.,
CPU direct R/W) with the designated I/O port address and
8-bit data.
The bit formats for the ISA Legacy I/O Registers plus two
chipset-specific configuration registers used for interrupt
mapping in the Core Logic module are given in this section.
The ISA Legacy registers are separated into the following
DMA Channel Control Registers, see Table 6-43
• DMA Page Registers, see Table 6-44
• Programmable Interval Timer Registers, see Table 6-45
• Programmable Interrupt Controller Registers, see Table
6-46
• Keyboard Controller Registers, see Table 6-47
• Real-Time Clock Registers, see Table 6-48
• Miscellaneous Registers, see Table 6-49 (includes 4D0h
and 4D1h Interrupt Edge/Level Select Registers)
Table 6-43. DMA Channel Control Registers
Bit Description
I/O Port 000h DMA Channel 0 Address Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 001h DMA Channel 0 Transfer Count Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 002h DMA Channel 1 Address Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 003h DMA Channel 1 Transfer Count Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 004h DMA Channel 2 Address Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 005h DMA Channel 2 Transfer Count Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 006h DMA Channel 3 Address Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 007h DMA Channel 3 Transfer Count Register (R/W)
Written as two successive bytes, byte 0, 1.
I/O Port 008h (R/W)
Read DMA Status Register, Channels 3:0
7 Channel 3 Request. Indicates if a request is pending.
0: No.
1: Yes.
6 Channel 2 Request. Indicates if a request is pending.
0: No.
1: Yes.
5 Channel 1 Request. Indicates if a request is pending.
0: No.
1: Yes.
4 Channel 0 Request. Indicates if a request is pending.
0: No.
1: Yes.
3 Channel 3 Terminal Count. Indicates if TC was reached.
0: No.
1: Yes.