TI380PCIA Datasheet, PDF (30/40 Pages) Texas Instruments – PCI BUS INTERFACE FOR THE TI380 COMMPROCESSORS

TI380PCIA
PCI BUS INTERFACE FOR THE TI380 COMMPROCESSORS™
SPWS035 – JUNE 1997
TI2000 configuration register (continued)
This is a read-only register with the following functions:
Bits 00 – 03: DMA. The four DMA bits indicate the DMA channel. At reset, these bits are 0x0. They are used
by TI2000-compatible software. The channel number has no meaning in terms of PCI bus DMA. However,
TI2000 drivers read this field. If it is set to 0xF, they operate in pseudo-DMA mode (see Table 9). Any other value
allows TI2000 drivers to use PCI DMA operation.
Table 9. DMA Bit Indicating DMA Channel Selection
3
2
1
0
0
0
0
0
0
0
0
1
0
0
1
0
.
.
.
.
1
1
1
1
DMA CHANNEL
DMA bus master
DMA bus master
DMA bus master
DMA bus master
Pseudo-DMA operation
Bits 04 – 07: INT. The four INT bits indicate the interrupt level as shown in Table 10. At reset, these bits are set
to 0x0. These bits echo the four LSBs of the interrupt line register.
Table 10. Interrupt Level of INT Bits 4 – 7
7
6
5
4
0
0
0
0
0
0
0
1
0
0
1
0
.
.
.
.
1
1
1
1
INTERRUPT LEVEL
0
1
2
...
15
Bit 08: Topology. Indicates whether the driver must initialize token-ring or Ethernet operation.
TI2000 drivers interpret the speed and topology bits together to determine whether to initialize the adapter under
4- or 16-Mbps token-ring, or 10-Mbps Ethernet operation (see Table 11).
Bit 09: Speed. Indicates whether the driver must initialize 4- or 16-Mbps Token-Ring Network™ operation.
See topology bit (bit 8).
These two bits echo bits 8 and 9 in the MISCCTRL register.
Table 11. Token-Ring/Ethernet Initialization
SPEED BIT 9
0
1
0
1
TOPOLOGY BIT 8
0
0
1
1
DESCRIPTION
Reserved
Ethernet
Token Ring, 16 Mbps
Token Ring, 4 Mbps
Bit 10: Connector. The Connector bit indicates the type of connector in use. TI2000 drivers do not currently use
this bit; however, it must always be read as 0 if it is not implemented in adapter logic. The value of this bit is
presented on pin DB9 / UTP of the TI380PCIA. Upon reset, this bit is 0. This bit echoes bit 10 of the MISCCTRL
register.
1 = D-Shell (DB9)
0 = UTP / 10BaseT
Token-Ring Network is a trademark of International Business Machines Corporation.
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