Section 6 Floating-Point Unit (FPU)
Rev.1.00 Dec. 13, 2005 Page 144 of 1286
REJ09B0158-0100
6.6
Graphics Support Functions
The SH-4A supports two kinds of graphics functions: new instructions for geometric operations,
and pair single-precision transfer instructions that enable high-speed data transfer.
6.6.1
Geometric Operation Instructions
Geometric operation instructions perform approximate-value computations. To enable high-speed
computation with a minimum of hardware, the SH-4A ignores comparatively small values in the
partial computation results of four multiplications. Consequently, the error shown below is
produced in the result of the computation:
Maximum error = MAX (individual multiplication result
×
2
–MIN (number of multiplier significant digits–1, number of multiplicand significant digits–1)
) + MAX (result value
×
2
–23
, 2
–149
)
The number of significant digits is 24 for a normalized number and 23 for a denormalized number
(number of leading zeros in the fractional part).
In a future version of the SH Series, the above error is guaranteed, but the same result between
different processor cores is not guaranteed.
FIPR FVm, FVn (m, n: 0, 4, 8, 12): This instruction is basically used for the following purposes:
•
Inner product (m
≠
n):
This operation is generally used for surface/rear surface determination for polygon surfaces.
•
Sum of square of elements (m = n):
This operation is generally used to find the length of a vector.
Since an inexact exception is not detected by an FIPR instruction, the inexact exception (I) bit in
both the FPU exception cause field and flag field are always set to 1 when an FIPR instruction is
executed. Therefore, if the I bit is set in the FPU exception enable field, FPU exception handling
will be executed.
FTRV XMTRX, FVn (n: 0, 4, 8, 12): This instruction is basically used for the following
purposes:
•
Matrix (4
×
4)
⋅
vector (4):
This operation is generally used for viewpoint changes, angle changes, or movements called
vector transformations (4-dimensional). Since affine transformation processing for angle +
parallel movement basically requires a 4
×
4 matrix, the SH-4A supports 4-dimensional
operations.
Summary of Contents for SH7780 Series
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Page 82: ...Section 1 Overview Rev 1 00 Dec 13 2005 Page 32 of 1286 REJ09B0158 0100 ...
Page 122: ...Section 3 Instruction Set Rev 1 00 Dec 13 2005 Page 72 of 1286 REJ09B0158 0100 ...
Page 146: ...Section 4 Pipelining Rev 1 00 Dec 13 2005 Page 96 of 1286 REJ09B0158 0100 ...
Page 196: ...Section 6 Floating Point Unit FPU Rev 1 00 Dec 13 2005 Page 146 of 1286 REJ09B0158 0100 ...
Page 292: ...Section 9 L Memory Rev 1 00 Dec 13 2005 Page 242 of 1286 REJ09B0158 0100 ...
Page 492: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Dec 13 2005 Page 442 of 1286 REJ09B0158 0100 ...
Page 674: ...Section 15 Clock Pulse Generator CPG Rev 1 00 Dec 13 2005 Page 624 of 1286 REJ09B0158 0100 ...
Page 692: ...Section 16 Watchdog Timer and Reset Rev 1 00 Dec 13 2005 Page 642 of 1286 REJ09B0158 0100 ...
Page 726: ...Section 18 Timer Unit TMU Rev 1 00 Dec 13 2005 Page 676 of 1286 REJ09B0158 0100 ...
Page 1032: ...Section 25 Audio Codec Interface HAC Rev 1 00 Dec 13 2005 Page 982 of 1286 REJ09B0158 0100 ...
Page 1150: ...Section 28 General Purpose I O GPIO Rev 1 00 Dec 13 2005 Page 1100 of 1286 REJ09B0158 0100 ...
Page 1184: ...Section 29 User Break Controller UBC Rev 1 00 Dec 13 2005 Page 1134 of 1286 REJ09B0158 0100 ...
Page 1266: ...Section 31 Electrical Characteristics Rev 1 00 Dec 13 2005 Page 1216 of 1286 REJ09B0158 0100 ...
Page 1328: ...Appendix Rev 1 00 Dec 13 2005 Page 1278 of 1286 REJ09B0158 0100 ...
Page 1336: ...Rev 1 00 Dec 13 2005 Page 1286 of 1286 REJ09B0158 0100 ...
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