Date: Tue, 23 Apr 1996 00:11:53 -0700
From: jordan@pongo.West.Sun.COM (Jordan Brown)
Subject: Item #346: Dallas Semiconductor 1385 Device Binding

P1275 Openboot Working Group Proposal -- Proposal #:346 Ver 0.2

Title:          Dallas Semiconductor 1385 Device Binding

Author:         Jordan Brown

Date:           22 April 1996

Ed/Tech:        Editorial, Technical

Synopsis:       Recast into device binding template.  Changes per 01/96.
		Add device state notes.

Doc & Version:  NVRAM device binding (Dallas Semiconductor 1385) (rename)

Problem:

This binding was approved with modifications as proposal 298.  This
proposal applies those modifications, recasts it into the device binding
template for publication, and proposes a few additions exposed by the
template outline.

Proposal:       

Dallas Semiconductor 1385 NVRAM
Device Binding to

IEEE 1275-1994
Standard for Boot (Initialization,
Configuration) Firmware

Revision 0.2
DRAFT

22 April 1996
Jordan Brown, SunSoft
Brian Horn, SunSoft

1.	Purpose of this Device Binding

This document specifies the application of Open Firmware to the NVRAM
portion of the Dallas Semiconductor 1385, as implemented on an ISA bus,
including device-specific requirements and practices for initialization,
properties, and methods.

2.	Revision History

	Revision 0.1, 30 October 1995
		Initial revision, proposal #298.
		Brian Horn, SunSoft.
	
	Revision 0.2, 22 April 1996
		Change device name.  Add backwards compatibility note.
		Editorial changes.  Fit to "device binding" template.
		Add device state notes.
		Jordan Brown, SunSoft

3.	References

[1]	IEEE Std 1275-1994 Standard for Boot (Initialization, Configuration)
	Firmware, Core Practices and Requirements
[2]	Device Support Extensions to IEEE Std 1275-1994 Standard for Boot
	(Initialization, Configuration) Firmware
	http://playground.sun.com/1275/bindings/DeviceX/
[3]	ISA/EISA/ISA-PnP binding to IEEE Std 1275-1994 Standard for Boot
	(Initialization, Configuration) Firmware
	http://playground.sun.com/1275/bindings/isa/

4.	Definition of Terms

5.	Device Characteristics (Informative)

	The Dallas Semiconductor 1385 is a combination of a Motorola
	MC146818 compatible realtime clock / CMOS RAM device and an
	NVRAM device.  This document describes the Open Firmware
	interface to the NVRAM portion of the device.

6.	Device-specific Configuration Variables

	None.

7.	Device Nodes

7.1.	Properties

7.1.1.	Open Firmware-defined Properties for Device Nodes

"name"
	If the Generic Names Recommended Practice is implemented by
	this package, this property shall have the value "nvram".

	If the Generic Names Recommended Practice is not implemented
	by this package, this property shall have the value "ds1385-nvram".

"compatible"
	If the Generic Names Recommended Practice is implemented by
	this package, this property shall have the value "ds1385-nvram".

"device_type"
	Standard Open Firmware property.  The value of this property
	shall be "nvram".

"reg"
	Standard Open Firmware property.  The value of this property
	shall follow the standard rules of Open Firmware devices, and
	in particular the definitions set forth in [3].

	The first entry shall define the address of the least significant
	byte of the "address" port.

	The second entry shall define the address of the most significant
	byte of the "address" port.

	The third entry shall define the address of the "data" port.

	Note:  Some existing implementations of support for this
	part use only two entries:  one entry describing the "address"
	registers and the second describing the "data" port.

7.1.2.	Device-specific Properties for Device Nodes

	None.

7.2.	Methods

7.2.1.	Open Firmware-defined Methods for Device Nodes

	As defined in [1] and [2].

7.2.1.1.	Device Arguments for "Open" Method

	None.

7.2.2.	Device-specific Methods for Device Nodes

	None.

8.	User Interface Commands

8.1.	Open Firmware-defined User Interface Commands

	None.

8.2.	Device-specific User Interface Commands

	None.

9.	Device State

9.1.	Device State When Client is Started

	The value of the "address" register is undefined.
	The contents of the NVRAM shall be internally consistent, in
	accordance with any applicable specifications.

9.2.	Device State Required When Client Calls Open Firmware

	The value of the "address" register is undefined.
	The contents of the NVRAM shall be internally consistent, in
	accordance with any applicable specifications.  The client
	may have changed the contents of the NVRAM.

	Note:  Internal consistency is guaranteed only on normal
	"Client Service" entries to Open Firmware; it is *not*
	guaranteed on, eg, breakpoints.

9.3.    Device State When Open Firmware Returns Control to Client

	The value of the "address" register is undefined.
	The contents of the NVRAM shall be internally consistent, in
	accordance with any applicable specifications.  Open Firmware
	may have changed the contents of the NVRAM.

10.	Other Commentary

	None.

[ P1275 Item #346 -- Received: Tue Apr 23 00:10:12 PDT 1996 ]