dhq(4) [ultrix man page]
dhq(4) Kernel Interfaces Manual dhq(4) Name dhq - DHQ11 communications interface Syntax device dhu0 at uba? csr 0160440 flags 0x?? vector dhurint dhuxint Description A DHQ11 provides eight communication lines with modem control. Each line attached to the DHQ11 communications multiplexer behaves as described in Input and output for each line can be set independently to run at any of 16 speeds. See for the coding. Bit i of flags can be specified for a DHQ11 to say that a line is not properly connected and that the line should be treated as hardwired with carrier always present. Thus, specifying ``flags 0x04'' in the specification of would cause the third line to be treated in this way. The driver operates under the control of the driver. Diagnostics dhu%d %d: DMA ERROR The indicated channel failed to transfer DMA data within 21.3 microseconds of the bus request being acknowledged or there was a memory par- ity error. dhu%d: DIAG. FAILURE The DHQ11 failed the diagnostics that run at initialization time. dhu%d: recv. fifo overflow The character input fifo overflowed before it could be serviced. This can happen if a hard error occurs when the CPU is running with ele- vated priority. Interrupts are disabled, and the system then prints a message on the console. dhu%d: DHU HARDWARE ERROR. TX.DMA.START failed The dhq failed to clear the start bit. Normally, this is cleared to signal that a DMA transfer has completed. Files Dialups See Also tty(4), MAKEDEV(8) dhq(4)
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cxa(4) Kernel Interfaces Manual cxa(4) Name cxa - CXA16 communications interface Syntax device dhu0 at uba0 csr 0160440 flags 0xffff vector dhurint dhuxint Description A CXA16 provides 16 data-leads-only communication lines with no modem control. The CXA16 conforms to RS423A. The device behaves and looks just like a DHV11 (with the exception of modem control and number of lines) and is specified in the configuration line the same as a DHV11 device. Each line attached to the CXA16 communications multiplexer behaves as described in and can be set to run at any of 16 speeds; see for the encoding. A flags field of 0xffff must be used to specify that all lines are to operate as hardwired. This is done to prevent the line from being treated as a modem control line. The dhu driver normally interrupts on each input character. The and devices operate under the control of the driver. Diagnostics dhu%d: receive fifo overflow The character input fifo overflowed before it could be serviced. This can happen if a hard error occurs when the CPU is running with ele- vated priority, as the system then prints a message on the console with interrupts disabled. This can cause a few input characters to be lost to users. It is not serious. dhu%d:%d DMA ERROR A DMA transfer error has occurred. The unit number and line number are printed. This means that the channel indicated has failed to transfer DMA data within 10.7 microseconds of the bus request being acknowledged or that there is a memory parity error. This may cause a few output characters to be lost. dhu%d: DIAG. FAILURE This indicates that the internal diagnostics have detected an error. dhu%d: DHU HARDWARE ERROR. TX.DMA.START failed The failed to clear the start bit. Normally, this is cleared to signal that a DMA transfer has completed. Files See Also tty(4), MAKEDEV(8) cxa(4)