NAME

dr − DR11-W general purpose interface driver

SYNOPSIS

/sys/conf/SYSTEM:
NDRdr11-w_units# DR11-W
 /etc/dtab:
#NameUnit#AddrVectorBrHandler(s) # Comments
dr?1724101245drintr # dr11-w (b-bus emulator)
dr?1724301305drintr # dr11-w (gc-bus emulator)
dr?1724501345drintr # 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:

•Word or byte transfers. 

•Programmed or direct memory access (DMA) block transfers. 

•Burst data transfers. 

•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:

DRGTTYGet DR11-W status. 

DRSTTYSet flags and function. 

DRSFUNSet function. 

DRSFLAGSet flags. 

DRGCSRGet CSR and WCR. 

DRSSIGSet signal for ATTN interrupt. 

DRESETReset DR11-W interface. 

DRSTIMESet timeout. 

DRCTIMESet timeout inactive. 

DROUTPUTPut word in output data register. 

DRINPUTGet word from input data register. 

DRITIMEDon’t ignore errors on timeout. 

FILES

/dev/dr[0-7]device special files
/dev/MAKEDEVscript to create special files
/dev/MAKEDEV.localscript 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. 

2nd Berkeley Distribution  —  January 27, 1996