Tadpole SPARCbook 3 series, Справочное руководство

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Display Interface
11-17
Power 9100 User Interface Controller
Bit 4 1 = Quad exception, operation must be done in software
Bit 3 1 = Requested quad is concave
Bit 2 1= Source coordinates for quad draw entirely outside
clipping window
Bit 1 1= Source coordinates for quad draw entirely inside clipping
window
Bit 0 1= Source coordinates for quad draw straddle clipping
window
Control and Condition
Registers These registers control and monitor P9100 operations. The addresses and
function of these registers is summarized in Table 11-8.
The control and condition registers are all 32-bit registers with valid data
contained only within the least significant byte – bits (7:0). A bit contains
a ‘1’ when the test condition is true.
Address Name Function
38002184 Out of Range Register This read-only register identifies x and y values that are out of
range for the current operation
3800218C Index Register This read-write register supplies the current index into the x
and y coordinates as a 2-bit binary integer. The value is used
for meta-coordinate computation.
38002190 Window Offset XY This read-write register supplies the x and y offsets of the
current window on the display as two packed 16-bit binary
integers.
38002194 Parameter Engine Window Minimum These read-write registers contains an exact copy of the
window minimum and maximum registers respectively.
38002198 Parameter Engine Window Maximum
380021A0 Y Clip Register These read-only registers provide the results of clip checks.
The P9100 updates these registers for every new set of x and y
values loaded into the coordinate registers.
380021A4 X Clip Register
380021A8 X Edge Less Than Register These read-only registers provide the results of checks on the
vertices of a requested drawing operation. The P9100 updates
these registers for every new set of x and y values loaded into
the coordinate registers.
380021AC X Edge Greater Than Register
380021B0 Y Edge Less Than Register
380021B4 Y Edge Greater Than Register
Table 11-8 Control and Condition Registers
S3GX_TRMBook Page 17 Friday, September 19, 1997 11:39 am