THE
COMPLETE AMIGA HARDWARE
REFERENCE MANUAL
APPENDIX G
AUTOCONFIG (TM)
The AUTOCONFIG protocol is designed to allow the dynamic assignment of
available address slots to expansion boards, eliminating the need for user
configuration via jumpers. Upon reset, each board appeals in turn at
$E80000. with readable identification information, most of which is in
one's complement format, stored in the high nibbles of the first $40
words ($80 bytes) of the board. This identification information includes
the size of the board, its address space preferences, type of board
(memory or other), and a unique Hardware Manufacturer Number assigned
by Commodore Amiga Technical Support, West Chester, Pennsylvania.
Each board contains configuration hardware including an address latch
appearing in the nibble at offset S0048 and a nibble at offset $004a.
When A23 through A16 of the assigned board base address are written to
this register, the board latches and appears at the assigned address,
then passes a signal called CONFIG-OUT that causes the next board to
appear at $E80000. To make certain types of boards less expensive, an
expansion board's write registers may be organized as
- Appendix G 335 -
either a byte-wide register or two nibble-wide registers. If the register
is nibble-wide then it must latch the low nibble of the assigned address
(at $4A) until the high nibble (at $48) is written.
This allows the following algorithm to work with either type of board:
Write the low order address nibble to offset $4A
Write the entire address byte to offset $48
Alternatively, many boards can be asked to "shut-up" (pass CONFIG-OUT and
stop responding) by writing to offset S004c of the board. A bit in the
nibble at offset $0008 flags whether a board supports shut-up.
All commercial expansion slot boards for the Amiga must implement the
AUTOCONFIG protocol. More in-depth machine-specific information on the
design and implementation of AUTOCONFIG boards is available from
Commodore Amiga Technical Support.
The Amiga operating system contains support for matching up disk-based
drivers with AUTO-CONFIG boards. Since 1.3, the OS also supports
initialisation of onboard ROM driver software.
As a general rule, applications should not attempt to AUTOCONFIG
expansion peripherals, but rather should allow the Amiga system software
to handle all automatic configuration. Many boards contain registers
which once activated could do irreparable damage, for example, data on a
user's hard disk could be lost if the board had been configured improperly.
However, certain types of low level stand-alone applications may need to
configure hardware such as RAM boards without using the Amiga operating
system. Such applications should only configure expansion RAM boards
(boards which ask to be added to the free memory list) and known
dedicated boards designed for specific applications. All other boards
should be shut-up if the board supports shut-up, or configured and
ignored if shut-up is not supported. (There are many boards which do not
support shut-up). Configuration of boards should only be attempted by
applications which take over the whole machine at reset. Presence of an
AUTOCONFIG board waiting for configuration is determined by comparing the
nibbles appearing at the initial AUTOCONFIG address with the valid values
for such nibbles in the specifications.
The AUTOCONFIG spec requires that boards be configured on boundaries that
match their space requirements. For example, a 1 MB memory board should
be configured on a 1 MB boundary.
There are two exceptions to this rule: boards with a 4 MB address space
are capable of being placed at S200000 and S600000 as well as being
placed on 4 MB boundaries; 8 MB boards can be placed at S200000. These
exceptions are necessary because the 8 MB space reserved for expansion in
the current machine begins at $200000.
DEBUGGING AUTOCONG BOARDS
If there is a defect in your configuration information, your board may be
ignored, may shut-up or may crash in a way that makes diagnosis
difficult. There is a simple trick allows you to test the configuration
information. Cut the CONFIGIN* line to your board and wire a switch into
the line. Wire in the switch such that when it is set one way, the
CONFIGIN* line will pass through
- 336 Appendix G -
from the bus to the board. This allows the board to respond to the
AUTOCONFIG process. When the switch is set the other way, it should be
wired such that the input to the board is forced high This will disable
the AUTOCONFIG of the board.
Set the switch so that the CONFIGIN* line is forced high, then bring up
the system. Your board will be invisible to the system software. Activate
a debugger, and flip the switch, Your board should now respond at the
normal $E80000 address. Your view of the board is identical to what the
operating system sees when configuring your board. You can compare the
bits with the expected values.
NOTE
The board to be debugged must be the last board in the system (closest to
the PC slots, away fm the power supply.) Boards downstream of the board
to be debugged will not be configured by the system.
ADDRESS SPECIFICATION TABLE
The following table describes the board identification information and
AUTOCONFIG registers which appear in the first $80 bytes of an AUTOCONFIG
board at configuration time.
NOTES
o Identification information is stored in the high nibbles of the even
(word) addresses at the start of an AUTOCONFIG board. For example, the
first two words of a board might contain $Cxxx 1xxx. The valid
information in these first two words would be the $C igh nibble of
the word at offset $00). then the $1 (high nibble of the word at offset
$02). Much of the information is interpreted by combining several
nibbles, with low to high address nlbbles containing high to low order
parts of the resulting value.
o All nibbles of information, except for those at offsets $00/02 and
$40/42, are stored in an inverted (one's complement) form and must be
exclusive OR'd with $F before interpreting them according to the table
below. Unused nibbles (the three other nibbles in each word) may not be
assumed to contain any particular value. All values written to the
AUTOCONFIG area, including the assigned address, are written uninverted.
o All addresses are shown here as offsets from the base address $E80000
where boards appear at configuration time, so offset $02 is at $E80002,
offset $04 at $E80004, etc.
- Appendix G 337 -
Board Offset
($00/02) 7 6 5 4 3 2 1 0 Description of nibbles
R/W info \___ ___/ \___ ___/
\/ \/
Nibble at $E80000 Nibble at $E80002
Figure G-1: How to read the Address Specification Table
NOTE
The bit numbering ( 7 6 5 4 3 2 1 0 ) is for use when two nibbles are to
be interpreted together as a byte. Physically, each nibble is the high
nibble of the word at its address (ie. bits 15 14 13 12).
Table G-1: Address Specification Table
OFFSET: Address 1 Address 2 Deacription
-------------------------------------------------------------------------
($00/02) 7 6 5 4 3 2 1 0___Board size 000=8meg 100512k
Read | | | | | \__|__/ 001=64k 101=1meg
Not Inverted | | | | | 010=128k 110=2meg
| | | | | 011=256k 111=4meg
| | | | \-------- 1 = Next card is also on this board
| | | \----------- 1 = Optional ROM vector valid
| | \-------------- 1 = Link into memory free list (RAM)
| \____________
\______________>---- Board type 00 = Reserved
01 = Reserved
10 = Reserved
11 = Current type
($04/06) 7 6 5 4 3 2 1 0 Manufacturers chosen product
Read \___ ___/ \___ ___/ number
Inverted \/ \/
Hi nibble Lo nibble
($08/0A) 7 6 5 4 3 2 1 0 (Remember - theae read inverted)
Read | | |_|_|_|_|_|_ Reserved - Should be 0 currently
Inverted | |
| \____________\ 0 = this board can be shut-up
| / 1 = this board ignores shut-up
|
\______________\ 0 = any space OK
/ 1 = 8 Meg area preferred
- 338 Appendix G -
OFFSET: Address 1 Address 2 Description (cont.)
-------------------------------------------------------------------------
(SOC/OE) 7 6 5 4 3 2 1 0
Read |_|_|_|_|_|_|_|_ Reserved - must be 0
Inverted
($10/12) 7 6 5 4 3 2 1 0 High byte of unique hardware
Read \___ ___/ \___ ___/ manufacturer number assigned
Inverted \/ \/ to manufacturer.
Hi nibble Lo nibble (Not developer number!)
(S14/16) 7 6 5 4 3 2 1 0 Low byte of unique hardware
Read \___ ___/ \___ ___/ manufacturer number assigned
Inverted \/ \/ to manufacturer.
Hi nibble Lo nibble (Not developer number!)
NOTE
Manufacturer number is assigned by Commodore Amiga Technical Support in
West Chester, Pennsylvania (CATS). Contact CATS for further information.
($18/1A) 7 6 5 4 3 2 1 0 Optional aerial #, 1st byte (msb)
($1C/lE) 7 6 5 4 3 2 1 0 Optional serial #, 2nd byte
($20/22) 7 6 5 4 3 2 1 0 Optional serial #, 3rd byte
($24/26) 7 6 5 4 3 2 1 0 Optional serial #, 4th byte (lsb)
Read
Inverted
(S28/2A) 7 6 5 4 3 2 1 0 Hi byte of optional ROM vector.
Read \___ ___/ \___ ___/
Inverted \/ \/
Hi nibble Lo nibble
(S2C/2E) 7 6 5 4 3 2 1 0 Lo byte of optional ROM vector.
Read \___ ___/ \___ ___/ If the "ROM vector valid" bit
Inverted \/ \/ is set in nibble S00 at start
Hi nibble Lo nibble of the board, this optional ROM
vector is the offset from the
board base to ROM driver
structures.
(S30/32) 7 6 5 4 3 2 1 0 Read - Reserved, must be 00
R/W Write - optional reset of
Inverted board base register to
pre-configuration address
($34/36) 7 6 5 4 3 2 1 0 Reserved, must be 00
(S38/3A) 7 6 5 4 3 2 1 0 Reserved, must be 00
(S3C/3E) 7 6 5 4 3 2 1 0 Reserved, must be 00
Inverted
- Appendix G 339 -
OFFSET: Address 1 Address 2 Description (cont.)
-------------------------------------------------------------------------
(S40/42) 7 6 5 4 3 2 1 0 Write Read
R/W | | | | | | | |
Not Inverted | | | | | | | \_ Interrupt enable Interrupt enable
| | | | | | \____ User definable Undefined
| | | | | \_______ Local reset Must be 0
| | | | \__________ User definable Undefined
| | | \_____________ User definable INT2 pending
| | \________________ User definable INT6 pending
| \___________________ User definable INT7 pending
\______________________ User definable Board pull INT
NOTE
Use of the S40/42 registers is an optional feature which can be implemented
by boards which generate interrrupts. They make it possible for
board-specific interrupt servers to determine if the current interrupt
is being generated by their board, or by some other hardware using the
same interrupt line.
(S44/46) 7 6 5 4 3 2 1 0 Reserved, read must be 00
R/W Write undefined
Inverted
(S48/4A) 7 6 5 4 3 2 1 0 Base add. register, write only.
Write Only \___ ___/ \___ ___/ These bits are compared with A23
Not Inverted \/ \/ through A16 (or fewer) to determine
Hi nibble Lo nibble the base address of the board.
($4C/4E) 7 6 5 4 3 2 1 0 Optional shut-up register.
Write Only \___ ___/ \___ ___/ Any write to $4C will cause
\/ \/ board to pass CONFIG-OUT and
\_________________\ and then never respond again
/ to any address, until RESET. A
bit in nibble $08 flags whether
the board can be shut-up.
(S50 through S7E) Reserved, must be 00
Inverted
Remember that an nibbles except S00/02 and $40/42 will actually appear
inverted from the values in the above table. For example, a "must be 0"
nibble will appear as $F, and flags and hex values will also be inverted
(i.e. a value of $1 will read as $E, etc).
- 340 Appendix G -
/*
* Examine all AUTOCONFIG(tm) boards in the system
*/
include "exec/types.h"
include "libraries/configvars.h"
struct Library *OpenLibrary();
struct ConfigDev *FindConfigDev();
struct Library *ExpansionBase;
void main()
{
struct ConfigDev *myCD=0;
ExpansionBase=OpenLibrary("expansion.library",0L);
while(myCD=FindConfigDev(myCD,-1L,-1L)) /* search for any ConfigDev */
{
printf("\n---ConfigDev structure found at location $%1x---\n",myCD);
/* These valuses are read directly from the board */
printf("er Manufacturer =");
printf("%d,",myCD->cd Rom.er Manufacturer);
printf("S%x,",myCD->cd Rom.er Manufacturer);
printf("(-$%4x)\n",-myCD->cd Rom.er Manufacturer);
printf("er Product =");
printf("%d,",myCD->cd Rom.er Product);
printf("$%x,",myCDС>cd Rom.er Product);
printf("(-$%x)\n",-myCD->cd Rom.er Product);
printf("er Type =$%x\n",myCD->cd Rom.er Type);
printf("er Flags =");
printf("$%x\n",myCD->cd Rom.er Flags);
/* These values are generated when the AUTOCONFIG(tm) software
* relocate the board
printf("cd BoardAddr =$%1x\n",myCD->cd BoardAddr);
printf("cd BoardSize =$%1x (%ldK)\n",
myCD->cd BoardSize,((ULONG)myCD->cd BoardSize)/1024);
printf("cd Flags =$%x\n",myCD->cd Flags);
}
CloseLibrary(ExpanionBase);
}
- Appendix G 341 -
End.
|