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 interrupts. 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 -
To Next Page
Loading...
