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dr(4) [bsd man page]

DR(4)							     Kernel Interfaces Manual							     DR(4)

dr - DR11-W general purpose interface driver SYNOPSIS
/sys/conf/SYSTEM: NDR dr11-w_units # DR11-W /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments dr ? 172410 124 5 drintr # dr11-w (b-bus emulator) dr ? 172430 130 5 drintr # dr11-w (gc-bus emulator) dr ? 172450 134 5 drintr # dr11-w (em-2 interface) major device number(s): raw: 12 minor device encoding: bits 0007 specify DR unit DESCRIPTION
The Digital Equipment 1981-82 Peripherals Handbook states the following about the DR11-W: The The DR11-W is a general purpose, direct memory access (DMA) interface to the PDP-11 UNIBUS or VAX UNIBUS. The DR11-W moves data directly between memory and the UNIBUS to and from the user's peripheral. It features: o Word or byte transfers. o Programmed or direct memory access (DMA) block transfers. o Burst data transfers. o User-controlled transfer rates up to memory speed. The DR11-W is a 53-line direct memory access (DMA) interface to the PDP-11 UNIBUS or VAX UBA, which allows the user to control data transfers between the host processor and a peripheral. The DR11-W has 32 data lines (for transferring 16-bit parallel data) and 21 control lines (for transferring control and status information. When used as an interprocessor buffer (IPB), the DR11-W allows data transfers between two processors. Interprocessor communication is accomplished by attaching one DR11-W to each processor UNIBUS or UBA and then cabling the two DR11-Ws together. There. Now you know as much about it as I do. A number of ioctl(2) calls apply to the dr devices, and have the form #include <pdpuba/drreg.h> ioctl(fildes, code, arg) int *arg; The applicable codes are: DRGTTY Get DR11-W status. DRSTTY Set flags and function. DRSFUN Set function. DRSFLAG Set flags. DRGCSR Get CSR and WCR. DRSSIG Set signal for ATTN interrupt. DRESET Reset DR11-W interface. DRSTIME Set timeout. DRCTIME Set timeout inactive. DROUTPUT Put word in output data register. DRINPUT Get word from input data register. DRITIME Don't ignore errors on timeout. FILES
/dev/dr[0-7] device special files /dev/MAKEDEV script to create special files /dev/MAKEDEV.local script to localize special files SEE ALSO
dtab(5), autoconfig(8) DIAGNOSTICS
dr%d: error csr=%b, eir=%b dr%d: timeout error BUGS
This interface is only available under 2.9BSD and 2.11BSD. No documentation exists on how to use it. 3rd Berkeley Distribution January 27, 1996 DR(4)

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DHU(4)							     Kernel Interfaces Manual							    DHU(4)

dhu - DHU-11 communications multiplexer SYNOPSIS
/sys/conf/SYSTEM: NDHU dhu_units # DHU11 /etc/dtab: #Name Unit# Addr Vector Br Handler(s) # Comments du ? 160020 310 5 dhurint dhuxint # dhu11 terminal mux major device number(s): raw: 4 minor device encoding: bits 0017 specify line on DHU unit bits 0060 specify DHU unit bit 0100 specify RTS/CTS flow control bit 0200 specifies non-blocking open (``CD always on'') DESCRIPTION
A DHU-11 provides 16 communication lines. Each line attached to the DHU-11 communications multiplexer behaves as described in tty(4). Input and output for each line may indepen- dently be set to run at any of 13 speeds (50, 200 and 38400 baud are not available); see tty(4) for the encoding. Bit 0200 of the minor device number for DHU lines may be set to say that a line is not properly connected, and that the line should be treated as hard-wired with carrier always present. Thus creating the special character device node "4, 130" via mknod /dev/ttyS2 c 4 130 would cause line ttyS2 to be treated in this way. Turning on bit 6 (adding 64) to the minor device number via mknod /dev/ttyS2 c 4 194 enables RTS/CTS flow control. The DHU-11 driver normally uses input silos and delays receiver interrupts by 20 milliseconds rather than taking an interrupt on each input character. FILES
/dev/tty[S-Z][0-9a-f] SEE ALSO
dhu(%d,%d) NXM. No response from UNIBUS on a DMA transfer within a timeout period. This has never been observed on a PDP-11 and is believed to be a carryover from the VAX driver when it was ported. It is not serious. dhu%d %d overruns. The character input silo overflowed before it could be serviced. This message is printed only at line close time rather than on each overrun error. Kernel printf's are not interrupt driven and caused more overruns by blocking interrupts for lengthy periods of time. NOTES
The driver currently does not make full use of the hardware capabilities of the DHU-11, for dealing with XON/XOFF flow-control or hard- wired lines for example. The 4 40-way cables are a pain. 3rd Berkeley Distribution May 31, 1997 DHU(4)
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