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CY(4) FreeBSD Kernel Interfaces Manual CY(4) NAME cy -- Cyclades Cyclom-{4, 8, 16}Y asynchronous comms board device driver SYNOPSIS cy0 at isa? iomem 0xd4000 irq 12 cy* at pci? DESCRIPTION This driver provides an interface to Cyclades Cyclom-4Y, Cyclom-8Y and Cyclom-16Y asynchronous multiport serial boards. These boards are based around Cirrus Logic CD1400 communication controllers. The device minor numbers for this driver are encoded as follows: d c c u u u u u - bits in the minor device number bits meaning ---- ------- uuuuu physical serial line (i.e., unit) to use 0-7 on a cyclom-8Y, 0-15 on a cyclom-16Y cc card number d dial-out flag DIAGNOSTICS cy0: port 0 ibuf overrun Incoming characters have been discarded due to a buffer overflow. cy0: port 0 fifo overrun Incoming characters have been discarded due to a CD1400 channel overrun. This is caused by interrupts not being ser- viced sufficiently quickly to prevent the 12 byte receive FIFO on a se- rial channel from overflowing. Reducing the value of the RX_FIFO_THRESHOLD #define from 6 to something smaller may help slow ma- chines avoid this problem. SEE ALSO com(4), intro(4), isa(4), pci(4), termios(4), tty(4) HISTORY Some ideas for the architecture of this driver's two-layer processing model were derived from the fas 2.10 driver by Uwe Doering <gemini@geminix.in-berlin.de> and the high-performance com driver by Bruce Evans <bde@kralizec.zeta.org.au>. This work was made possible through the donation of a Cyclom-8Y board by the manufacturer, Cyclades Corporation. However, neither Cyclades nor the author make any warranties regarding this software, nor guarantees of support. AUTHORS The driver was written by Andrew Herbert <andrew@werple.apana.org.au>. BUGS There is currently no BREAK handling - breaks are ignored. There is no support for bad-character reporting, except via PARMRK. The Cyclom-[48]Y boards do not listen to the RTS signal for receiver flow control. FIFO overruns are only logged when the termios IGNPAR setting is enabled. FreeBSD 13.0 July 23, 2020 FreeBSD 13.0
NAME | SYNOPSIS | DESCRIPTION | DIAGNOSTICS | SEE ALSO | HISTORY | AUTHORS | BUGS
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