General Standards Corporation PCI-SIO4, Руководство пользователя

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PCI-SIO4 User Manual
General Standards Corporation
8302A Whitesburg Drive Huntsville, AL 35802, Phone: (256) 880-8787
17
Channel 3 CTS on the lower portion of the cable. This will cause these signals
on the cable to go from a tri-state condition to a driven state.
D4 Enable the Channel 3 Receivers for the Upper portion of the cable (will load the cable)
Writing a ‘1’ to this bit will turn on the receivers for the Channel 3 upper portion
of the cable. The signals that are turned on are the Channel 3 RxD and Channel
3 DCD on the upper portion of the cable. This will cause these signals on the
cable to go from a tri-state condition to a loaded condition.
D5 Enable the Channel 3 Receivers for the Lower portion of the cable (will load the cable)
Writing a ‘1’ to this bit will turn on the receivers for the Channel 3 lower portion
of the cable. The signals that are turned on are the Channel 3 RxD and Channel
3 DCD on the lower portion of the cable. This will cause these signals on the
cable to go from a tri-state condition to a loaded condition.
D6 Reserved
D7 Reset Zilog for Channel 3-4 (Pulsed)
Writing a ‘1’ to this bit will cause the channel 3-4 Zilog Z16C30 USC to be
reset. This bit is a self-timed pulse; therefore, it is not necessary for software to
return to clear this bit, it will clear itself. Note, that after power up and after any
reset to this component, the next access to channel 3 or channel 4 USC must be a
write of 0x00 to offset 0x00 of channel 3 USC.
D8 Channel 3 Tx FIFO Empty (TRUE == 0)
D9 Channel 3 Tx FIFO Almost Empty (TRUE == 0)
D10 Channel 3 Tx FIFO Almost Full (TRUE == 0)
D11 Channel 3 Tx FIFO Full (TRUE == 0)
D12 Channel 3 Rx FIFO Empty (TRUE == 0)
D13 Channel 3 Rx FIFO Almost Empty (TRUE == 0)
D14 Channel 3 Rx FIFO Almost Full (TRUE == 0)
D15 Channel 3 Rx FIFO Full (TRUE == 0)
The FIFO status flags are active low indicators of the current FIFO status. These flags are
continuously being updated every 33ns. A value of ‘0’ indicates that the current status is true and
a value of ‘1’ indicates that it is not true. There are only 5 valid combinations for each nibble
(D8..D11 or D12..D15). These combinations are as follows:
0xC 1100 Almost Empty and Empty
0xD 1101 Almost Empty but not Empty
0xF 1111 In between Almost Empty and Almost Full
0xB 1011 Almost Full but not full
0x3 0011 Almost Full and Full
2.1.16 C
HANNEL
4 T
X
A
LMOST
: (LOC 0
X
40)
D0..31 Channel 4 Tx Almost Data
The data in this regis ter is used for programming the Almost Flags of the Tx
FIFOs for this channel.
D0..15 is used for the Almost Empty Flag
D16..31 is used for the Almost Full Flag
2.1.17 C
HANNEL
4 R
X
A
LMOST
: (LOC 0
X
44)
D0..31 Channel 4 Rx Almost Data
The data in this register is used for programming the Almost Flags of the Tx FIFOs for
this channel.