com(4) [netbsd man page]
COM(4) BSD Kernel Interfaces Manual COM(4) NAME
com -- serial communications interface for RS-232C SYNOPSIS
com0 at isa? port "IO_COM1" irq 4 com1 at isa? port "IO_COM2" irq 3 com* at acpi? com* at cardbus? com* at isapnp? com* at mca? slot ? com* at mhzc? com* at ofisa? com* at pcmcia? com* at pcmcom? com* at pnpbios? index ? com* at puc? port ? com* at xirc? options COM_HAYESP options PPS_SYNC options PPS_TRAILING_EDGE options RND_COM Arm32 com0 at mainbus? base 0x00210fe0 com1 at mainbus? base 0x00210be0 HP 9000/300 and 400 Series com* at dio? scode ? com* at frodo? offset ? HP 9000/700 and 800 Series com* at dino? com* at gsc? com* at ssio? IBM PowerPC 4xx com* at opb? SPARC com* at ebus? com* at obio0 DESCRIPTION
The com driver provides support for NS8250-, NS16450-, and NS16550-based EIA RS-232C (CCITT V.28) communications interfaces. The NS8250 and NS16450 have single character buffers, and the NS16550 has a 16 character buffer. Input and output for each line may set to one of following baud rates; 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, or 115200, or any other baud rate which is a factor of 115200. The ttyXX devices are traditional dial-in devices; the dtyXX devices are used for dial-out. (See tty(4).) options COM_HAYESP adds support for the Hayes ESP serial board. options PPS_SYNC enables code to use the Data Carrier Detect (DCD) signal line for attachment to an external precision clock source (e.g., GPS, CDMA) which generates a Pulse Per Second (PPS) signal. This is used by ntpd(8) to discipline the system clock, and more accurately count/measure time. See options(4) for more discussion. With options RND_COM enabled, the com driver can be used to collect entropy for the rnd(4) entropy pool. The entropy is generated from interrupt randomness. Arm32 specific If ``flags 1'' is specified, the com driver will not set the MCR_IENABLE bit on the UART. This is mainly for use on AST multiport boards, where the MCR_IENABLE bit is used to control whether or not the devices use a shared interrupt. FILES
/dev/dty00 /dev/dty01 /dev/dty02 /dev/tty00 /dev/tty01 /dev/tty02 DIAGNOSTICS
com%d: %d silo overflows The input ``silo'' has overflowed and incoming data has been lost. com%d: weird interrupt: iir=%x The device has generated an unexpected interrupt with the code listed. SEE ALSO
acpi(4), ast(4), cardbus(4), isa(4), isapnp(4), mca(4), mhzc(4), ofisa(4), options(4), pcmcia(4), pcmcom(4), pnpbios(4), puc(4), rtfps(4), tty(4), xirc(4), ntpd(8) HISTORY
The com driver was originally derived from the HP9000/300 dca driver. BUGS
Data loss is possible on busy systems with unbuffered UARTs at high speed. The name of this driver and the constants which define the locations of the various serial ports are holdovers from DOS. BSD
June 7, 2011 BSD
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ZSTTY(4) BSD Kernel Interfaces Manual ZSTTY(4) NAME
zstty, zsc, zs -- Zilog 8530 Serial Communications Controller (SCC) for RS-232C, RS-422, and RS-423 SYNOPSIS
options PPS_SYNC options PPS_TRAILING_EDGE alpha (DEC 3000) zsc0 at ioasic? offset 0x100000 zsc1 at ioasic? offset 0x180000 zstty0 at zsc0 channel ? # serial ports on B channels zstty2 at zsc1 channel ? # serial ports on B channels lkkbd0 at zsc1 channel ? # keyboard port on A channels vsms0 at zsc0 channel ? # mouse port on A channels cesfic zsc* at mainbus0 zstty* at zsc? channel ? mac68k and macppc zsc0 at obio? zstty* at zsc? channel ? options ZS_TXDMA mipsco zsc0 at obio0 addr 0xbb000000 zstty0 at zsc0 channel 0 zstty1 at zsc0 channel 1 mvme68k zsc* at pcc? ipl 4 zsc* at pcctwo? ipl 4 zstty* at zsc? channel ? news68k zsc0 at hb0 addr 0xe0d40000 ipl 5 vect 64 flags 0x0 # news1700 zsc0 at hb1 addr 0xe1780000 ipl 5 vect 64 flags 0x1 # news1200 zstty0 at zsc0 channel 0 zstty1 at zsc0 channel 1 newsmips zsc0 at hb0 addr 0xbfec0000 level 1 flags 0x0 # on-board zsc1 at hb0 addr 0xb8c40100 level 1 flags 0x1 # expansion board zsc2 at hb0 addr 0xb8c40104 level 1 flags 0x1 zsc0 at ap? zstty0 at zsc0 channel 0 zstty1 at zsc0 channel 1 zstty2 at zsc1 channel 0 zstty3 at zsc1 channel 1 zstty4 at zsc2 channel 0 zstty5 at zsc2 channel 1 next68k zsc0 at intio? ipl 5 #zsc1 at intio? ipl 5 zstty0 at zsc0 channel 0 # ttya zstty1 at zsc0 channel 1 # ttyb sgimips zsc* at hpc0 offset ? zstty* at zsc? channel ? sparc zs0 at mainbus0 # sun4c zs0 at obio0 # sun4m zs0 at obio0 addr 0xf1000000 level 12 # sun4/200 and sun4/300 zs0 at obio0 addr 0x01000000 level 12 # sun4/100 zstty0 at zs0 channel 0 # ttya zstty1 at zs0 channel 1 # ttyb zs1 at mainbus0 # sun4c zs1 at obio0 # sun4m zs1 at obio0 addr 0xf0000000 level 12 # sun4/200 and sun4/300 zs1 at obio0 addr 0x00000000 level 12 # sun4/100 kbd0 at zs1 channel 0 # keyboard ms0 at zs1 channel 1 # mouse zs2 at obio0 addr 0xe0000000 level 12 # sun4/300 zstty2 at zs2 channel 0 # ttyc zstty3 at zs2 channel 1 # ttyd sun2 zs0 at obio0 addr 0x002000 # 2/120, 2/170 zs1 at obmem0 addr 0x780000 # 2/120, 2/170 zs0 at obio0 addr 0x7f2000 # 2/50 zs1 at obio0 addr 0x7f1800 # 2/50 zs2 at mbmem0 addr 0x080800 # 2/120, 2/170 (first sc SCSI) zs3 at mbmem0 addr 0x081000 # 2/120, 2/170 (first sc SCSI) zs4 at mbmem0 addr 0x084800 # 2/120, 2/170 (second sc SCSI) zs5 at mbmem0 addr 0x085000 # 2/120, 2/170 (second sc SCSI) zstty* at zs? channel ? # ttya kbd0 at zstty? # keyboard ms0 at zstty? # mouse sun3 zstty0 at zsc1 channel 0 # ttya zstty1 at zsc1 channel 1 # ttyb kbd0 at zsc0 channel 0 # keyboard ms0 at zsc0 channel 1 # mouse x68k zsc0 at intio0 addr 0xe98000 intr 112 zstty0 at zsc0 channel 0 # built-in RS-232C ms0 at zsc0 channel 1 # standard mouse #zsc1 at intio0 addr 0xeafc00 intr 113 #zstty2 at zsc1 channel 0 #zstty3 at zsc1 channel 1 #zsc2 at intio0 addr 0xeafc10 intr 114 #zstty4 at zsc2 channel 0 #zstty5 at zsc2 channel 1 DESCRIPTION
The zstty driver provides TTY support for Zilog 8530 Dual UART chips. Input and output for each line may set to any baud rate in the range 50 to 38400 (and higher on some machines). The PPS_SYNC option enables code to use the Data Carrier Detect (DCD) signal line for attachment to an external precision clock source (e.g., GPS, CDMA) which generates a Pulse Per Second (PPS) signal. This is used by ntpd(8) to discipline the system clock, and more accurately count/measure time. See options(4) for more discussion. FILES
alpha /dev/ttyB0 /dev/ttyB1 others /dev/ttya /dev/ttyb DIAGNOSTICS
zs0*: fifo overflow The on-chip ``FIFO'' has overflowed and incoming data has been lost. This generally means the machine is not responding to inter- rupts from the ZS chip fast enough, which can be remedied only by using a lower baud rate. zs0*: ring overflow The software input "ring" has overflowed. This usually means input flow-control is not configured correctly (i.e. incorrect cable wiring). SEE ALSO
kbd(4), ms(4), options(4), scc(4), tty(4), ntpd(8) HISTORY
The zstty driver was derived from the sparc zs driver supplied with 4.4BSD UNIX. CAVEATS
/dev/ttyB1 on alpha is created by MAKEDEV(8) with minor number 2, so the corresponding device should be zstty2, not zstty1. BUGS
The old Zilog 8530 chip has a very small FIFO (3 bytes?) and therefore has very strict latency requirements for the interrupt service rou- tine. This limits the usable baud rates on many machines. BSD
June 7, 2011 BSD