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1
1 : FB read/write in progress.
Bit 2: Indicates V - sync.
Bit 3: Indicates the presence of av- sync interrupt if status is 1.
B;+
4: Indicates the presence of a command completion interrupt if status is 1.
Bit 5: Version number; 0 at present.
Bit 6: 0: B/W; 1: Color
(Write)
Bit O: Resets the raster operation controller.
O: Reset.
1: Execute possible.
Bit 1: Inhibits the kanji ROM.
O: Reset. (In this status, the source/destination address regis - ter must be set to
O. This is to prevent ROM data from being output to the HD bus.)
1: Enable.
Bit 3: v- sync interrupt enable/clear.
O: Clear/disable.
1: Enable.
Bit 4: Command completion interrupt enable/clear.
0: Clear/disable.
1: Enable.
(A reset signal from the host sets all bits to 0.)
3-9-5. Raster operation command registers
The DSC - 008 is basically identical to the NWB - 225A in that frame buffer operations
are possible by means of raster operation
( rop)
commands. The raster operation
commands perform the following functions:
1) Copying from a source rectangle to a destination rectangle within one plane in
the FB.
2) Copying from a source rectangle on one FB plane to destination rectangles in all
planes.
3) Reads and writes from the host to the FB destination rectan-gle.
4) 1 - pixel writes in the FB.
Rop commands are conveyed using an address (Al6 - Al) and data ( Dll - 0) from the
host.
Conveyed as address:
The register setting which is specified as a value (Al6 - Al5 and A6 - Al).
Setting specifying whether or not to execute the rop (Al4).
Setting specifying whether or not to set the shift count (Al3).
Y address (Al2 - Al) (AO is always 0 for word access.)
Conveyed as data:
Rop operating mode (D7 - DO)
Rop function ( D3 - DO)
Rop mask data (Dl5 - DO)
Write data ( Dl5 - DO)
Write plane setting (D7 - D)
X address ( Dll - DO)
See Fig. 2.(page 3-57, 3-58)
The following registers must be set to execute a rop:
NWS-1510/1530/1580
3-43
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