DragonOpsIO.mesa
Copyright © 1986 by Xerox Corporation. All rights reserved.
Frailong, October 13, 1986 1:43:18 pm PDT
Abstract description of basic Dragon I/O instructions
DragonOpsIO: CEDAR DEFINITIONS
~ BEGIN
Basic IO operations
DevID: TYPE ~ [0..1024);
DynaBus devices have a 10-bit device ID that identify them on the DynaBus. When doing IO to a DynaBus device, part of its ID is used to differentiate devices. Refer to DynaBus documentation for details.
WORD: TYPE ~ LONG CARDINAL;
A 32-bits quantity, no intepretation on contents. The LONG prefix is of use only so that this may be compiled using Dorado Cedar. It should be removed for Dragon Cedar.
IOAddress: TYPE ~ RECORD [v: WORD];
Any Dragon IO address. v may be any 32-bit value. Refer to DynaBus specification for interpretation on DynaBus, and to specific device documentation for specific values.
IORead: PROC [addr: IOAddress] RETURNS [value: WORD];
Performs a DynaBus IORead operation at the specified address and returns the result
IOWrite: PROC [addr: IOAddress, value: WORD];
Performs a DynaBus IOWrite operation of value at the specified address
BIOWrite: PROC [addr: IOAddress, value: WORD];
Performs a DynaBus BIOWrite operation of value at the specified address. A number of DynaBus devices may perform the write operation
END.