General Standards Corporation PCIe-SIO4BX2, User Manual

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13 Rev NR
D14:13 Cable RTS Output Source
D14 D13 Output Source Notes
0 0 USC_CTS Output
USC_CTS field (D10:D9) must equal ‘11’
0 1 RTS Output Rx FIFO Almost Full
1 0
‘0’
Drive low
1 1
‘1’
Drive Hi
D12:11 USC_DCD Direction Setup

If DCD is used as GPIO, set this field to ‘00’ and set Pin Source Register
D16:D15 for output / Pin Status Register D3 for input.

If set, the DCD direction must agree with the USC DCD setup (USC IOCR
D13:12) to ensure proper operation.

If field set to ‘11’ (Output), DCD Source field (D16:15) must be set to ‘00’.
D12 D11 DCD Buffer Direction USC IOCR D13:D12 Setup
0 0 Buffer Disabled
XX (Don’t Care)
0 1 Input from IO Connector - DCD 0X (Input)
1 0 Reserved
XX (Don’t Care)
1 1 Output to IO Connector 1X (Output)
D10:9
USC_CTS Direction Setup

If CTS is used as GPIO, set this field to ‘00’ and set Pin Source Register
D14:D13 for output / Pin Status Register D2 for input.

If set, the CTS direction must agree with the USC CTS setup (USC IOCR
D15:14) to ensure proper operation.

If field set to ‘11’ (Output), RTS Source field (D14:13) must be set to ‘00’.
D10 D9 CTS Buffer Direction USC IOCR D15:D14 Setup
0 0 Tristate
XX (Don’t Care)
0 1 Input from IO Connector – CTS 0X (Input)
1 0 Reserved
XX (Don’t Care)
1 1 Output to IO Connector 1X (Output)
D8:6
Cable TxC Source
D8 D7 D6 TxC Source
0 0 0 Prog Clock
0 0 1 Inverted Prog Clock
0 1 0
‘0’ (Drive Line Lo)
0 1 1
‘1’ (Drive Line Hi)
1 0 0 USC_TxC
1 0 1 USC_RxC
1 1 0 Cable RxC Input
1 1 1 Cable RxAuxC Input