PCI1031 Datasheet, PDF (87/100 Pages) Texas Instruments – PCI-TO-PC CARD16 CONTROLLER UNIT

PCI1031
PCI-TO-PC CARD16 CONTROLLER UNIT
SCPS008B – FEBRUARY 1996 – REVISED DECEMBER 1997
DMA mode register
Bit
7
6
5
4
3
2
1
0
Name
DMA mode
Type
R/W
R/W
R/W
R/W
R/W
R/W
R
R
Default
0
0
0
0
0
0
0
0
Register: DMA mode
Type:
Read only, read/write (see individual bit descriptions)
Offset:
DMA base address + 0Bh
Default: 00h
Size:
One byte
Description: The DMA mode register. Refer to Table 47 for a complete description of the register contents.
Table 47. DMA Mode Register
BIT TYPE
FUNCTION
Mode select bits. The PCI1031 uses bits 7–6 to determine which DMA transfer mode to use: single, block or demand. This
field is encoded as:
7–6
R/W
00 = Demand mode select (default)
01 = Single mode select
10 = Block mode select
11 = Reserved
Address increment/decrement. The PCI1031 uses bit 5 to select the memory address in the current/base register to
increment or decrement after each data transfer. This is in accordance with the 8237 DMA controller use of this register
5
R/W bit. Bit 5 is encoded as:
0 = Addresses increment (default)
1 = Addresses decrement
Autoinitialization bit. In the PCI1031, bit 4 selects autoinitialization. Bit 4 is encoded as:
4
R/W
0 = Autoinitialization disabled (default)
1 = Autoinitialization enabled
Transfer type. Bits 3–2 select the type of DMA transfer to be performed. A DMA write transfer moves data from the PC
Card to memory. A DMA read transfer moves data from memory to the PC Card. This field is encoded as:
3–2
R/W
00 = No transfer selected (default)
01 = Write transfer
10 = Read transfer
11 = Reserved
Reserved. Bits 1–0 are read only and return 0s when read. The 8237 DMA controller uses these register bits to select
1–0
R
the current channel number for programming. The master DMA device uses bits 1–0 to select the current device. Devices
such as the PCI1031 do not require bits 1–0.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
87