Commodore Amiga A1000, Hardware Reference Manual

Page: 275 / 380

BPLxDAT 110 W D Bit plane x data (parallel-to-serial convert)
These registers receive the DMA data fetched from
RAM by the bit plane address pointers described
above. They may also be written by either
microprocessor. They act as a six-word parallel-
to-serial buffer for up to six memory bit planes
(x=1-6). The parallel-to-serial conversion is
triggered whenever bit plane #1 is written,
indicating the completion of all bit planes for
that word (16 pixels). The MSB i9 output first,
and is, therefore, always on the left.
BPLxPTH 0E0 W A = Bit plane x pointer (high 3 bits)
BPLxPTL 0E2 W A Bit plane x pointer (low 15 bits)
This pair of registers contains the 18-bit pointer to
the address of bit-plane x (x21,2,3,4,5,6) DMA data.
This pointer must be reinitialized by the processor
or copper to point to the beginning of bit plane data
every vertical blank time.
CLXCON 098 W D Collision control
This register controls which bit-planes are
included (enabled) in collision detection and
their required state if included. It also controls
the individual inclusion of odd-numbered sprites
in the collision detection by logically OR-ing
them with their corresponding even-numbered sprite.
BIT FUNCTION DESCRIPTION
-----------------------------------------------------
15 ENSP7 Enable sprite 7 (ORed with sprite 6)
14 ENSP5 Enable sprite 5 (ORed with sprite 4)
13 ENSP3 Enable sprite 3 (ORed with sprite 2)
12 ENSP1 Enable sprite 1 (ORed with sprite 0)
11 ENBP6 Enable bit plane 6 (match required for collision)
10 ENBP5 Enable bit plane 5 (match required for collision)
09 ENBP4 Enable bit plane 4 (match required for collision)
08 ENBP3 Enable bit plane 3 (match required for collision)
07 ENBP2 Enable bit plane 2 (match required for collision)
06 ENBP1 Enable bit plane 1 (match required for collision)
05 NVBP6 Match value for bit plane 6 collision
04 MVBP5 Match value for bit plane 5 collision
03 MVBP4 Match value for bit plane 4 collision
02 MVBP3 Match value for bit plane 3 collision
01 MVBP2 Match value for bit plane 2 collision
00 MVBP1 Match value for bit plane 1 collision
NOTE: Disabled bit planes cannot prevent collisions. Therefore if all bit
planes are disabled, collisions will be continuous, regardless of the
match values.
- 266 Appendix A -