1*61587Sbostic.\" Copyright (c) 1986, 1991, 1993 2*61587Sbostic.\" The Regents of the University of California. All rights reserved. 330226Ssam.\" 443580Strent.\" %sccs.include.redist.man% 530226Ssam.\" 6*61587Sbostic.\" @(#)ace.4 8.1 (Berkeley) 06/05/93 736754Sbostic.\" 847673Scael.Dd 947673Scael.Dt ACE 4 tahoe 1047673Scael.Os BSD 4.2 1147673Scael.Sh NAME 1247673Scael.Nm ace 1347673Scael.Nd 1447673Scael.Tn ACC 1547673Scael10 Mb/s Ethernet interface 1647673Scael.Sh SYNOPSIS 1747673Scael.Cd "device ace0 at vba? csr 0xffff0000 flags 0xfff80000 vector acecint acerint" 1847673Scael.Sh DESCRIPTION 1930226SsamThe 2047673Scael.Nm ace 2130226Ssaminterface provides access to a 10 Mb/s Ethernet network through 2247673Scaelan 2347673Scael.Tn ACC 2447673Scaelcontroller. 2547673Scael.Pp 2647673ScaelThe hardware has 32 kilobytes of dual-ported memory on the 2747673Scael.Tn VERSAbus . 2830226SsamThis memory 2930226Ssamis used for internal buffering by the board, and the interface code reads 3047673Scaelthe buffer contents directly through the 3147673Scael.Tn VERSAbus . 3247673ScaelThe address of this memory is given in the 3347673Scael.Ar flags 3447673Scaelfield 3530226Ssamin the configuration file. 3647673Scael.Pp 3730226SsamEach of the host's network addresses 3847673Scaelis specified at boot time with an 3947673Scael.Dv SIOCSIFADDR 4047673Scael.Xr ioctl 2 . 4147673ScaelThe 4247673Scael.Nm ace 4330226Ssaminterface employs the address resolution protocol described in 4447673Scael.Xr arp 4 4530226Ssamto dynamically map between Internet and Ethernet addresses on the local 4630226Ssamnetwork. 4747673Scael.Pp 4847673ScaelThe interface normally tries to use a 4947673Scael.Dq trailer 5047673Scaelencapsulation 5130226Ssamto minimize copying data on input and output. 5247673ScaelThe use of trailers is negotiated with 5347673Scael.Tn ARP . 5430226SsamThis negotiation may be disabled, on a per-interface basis, 5547673Scaelby setting the 5647673Scael.Dv IFF_NOTRAILERS 5747673Scaelflag with an 5847673Scael.Dv SIOCSIFFLAGS 5947673Scael.Xr ioctl . 6047673Scael.Pp 6130226SsamThe device implements an exponential backoff algorithm 6230226Ssamwhen notified of a collision on the cable. This algorithm utilizes 6330226Ssama table of random numbers setup by the system at boot time. 6430226SsamThe delay is done in the controller. 6547673Scael.Sh DIAGNOSTICS 6647673Scael.Bl -diag 6747673Scael.It "ace%d: stray xmit interrupt, xnct %d." 6830226SsamAn unexpected transmission complete interrupt was received; 6930226Ssamthe interrupt is ignored. 7047673Scael.It "ace%d: can't handle af%d." 7130226SsamThe interface was handed 7230226Ssama message with addresses formatted in an unsuitable address 7330226Ssamfamily; the packet was dropped. 7447673Scael.El 7547673Scael.Sh SEE ALSO 7647673Scael.Xr intro 4 , 7747673Scael.Xr inet 4 , 7847673Scael.Xr arp 4 7947673Scael.Sh HISTORY 8047673ScaelThe 8147673Scael.Nm 8247673Scaeldriver appeared in 8347673Scael.Bx 4.3 tahoe . 8447673Scael.Sh BUGS 8530226SsamThe hardware is not capable of talking to itself. The software 8630226Ssamimplements local sending and broadcast by sending such packets to the 8730226Ssamloop interface. This is a kludge. 8847673Scael.Pp 8930226SsamThe device doesn't autoconfigure its interrupt vector; it is set 9030226Ssamat 0x90 + eight times the unit number. 91