*Notice: The information in this document is subject to change without notice
Tsi301
Notes
Tsi301 HyperTransport to PCI User Manual
5-36
2:0
RW_R
5h
TrcvThrshld - this register sets the threshold for determining when the target
receive FIFO is full. The FIFO is considered full when the count of items in the
FIFO exceeds this value. Since 2 or more items may be received by PCI after
the disconnect is initiated, this value should never be set above 5 and must
never be set to 0.
Note:
The target receive FIFO is used to store requests and
write data when the Tsi301 is acting as a target on the PCI
bus. When the FIFO is considered full, it causes PCI discon-
nects.
In Pass1, this CSR did not exist. Hardware
behaved as if this CSR was always set to 5.
Link Impedance Control 0
Offset 73h–70h
Bits
Type
Reset
Description
31:27
R
00h
Current TxUp - current impedance value for transmit pull-up resistor.
26:22
R
00h
Current TxDown - current impedance value for transmit pull-down resistor.
21:17
R
00h
Current RxTerm - current impedance value for receive termination resistor.
16:12
RW
00h
RxTerm - impedance value for receive termination resistor. Used when RxSel is
set. Not persistent through warm reset.
11
RW
0
RxSel - enables use of CSR receive impedance values. Not persistent through
warm reset.
10:6
RW
00h
TxUp - impedance value for transmit pull-up resistor. Used when TxSel is set.
Not persistent through warm reset.
5:1
RW
00h
TxDown - impedance value for transmit pull-down resistor. Used when TxSel is
set. Not persistent through warm reset.
0
RW
0
TxSel - enables use of CSR transmit impedance values. Not persistent through
warm reset.
Link Impedance Control 1
Offset 77h–74h
Bits
Type
Reset
Description
31:27
R
00h
Current Tx Up - current impedance value for transmit pull-up resistor.
26:22
R
00h
Current Tx Down - current impedance value for transmit pull-down resistor.
21:17
R
00h
Current Rx Term - current impedance value for receive termination resistor.
16:12
RW
00h
Rx Term - impedance value for receive termination resistor. Used when RxSel
is set. Not persistent through warm reset.
11
RW
0
Rx Select - enables use of CSR receive impedance values. Not persistent
through warm reset.
10:6
RW
00h
Tx Up - impedance value for transmit pull-up resistor. Used when TxSel is set.
Not persistent through warm reset.
5:1
RW
00h
Tx Down - impedance value for transmit pull-down resistor. Used when TxSel is
set. Not persistent through warm reset.
0
RW
0
Tx Select - enables use of CSR transmit impedance values. Not persistent
through warm reset.
PCI Control 2
Offset 6Fh–6Fh<Emphasis> (Continued)
Bit
Type
Reset
Description