W90221X Winbond Electronics Corp America, W90221X Datasheet - Page 217

• Manufacturer Part Number: W90221X
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

Exception : None
Saturation
Format:
Purpose: To test accumulate register {HI, LO} overflow, then saturate the
accumulate register {HI, LO}
Description: To test accumulate register {HI, LO} overflow, and if the accumulate
register {HI, LO} is overflow, then saturate the accumulate register, the accumulate
register is not overflow, then perform a null operation.
multiply/accumulate operations, so that temporary overflows do NOT occur the
accumulator to saturate.
multiply/accumulate. If half word operation, test the high-order 33-bits of the
accumulate register. The possible results after execution of saturation instruction is
shown in Table I. If word operation, test the carry bit (hidden 4-bits) and sign bit, the
possible results after execution of saturation instruction is shown in Table II.
operation
Table I. (Halfword saturation operation mode).
*HMV HI[0]
*HMV : HMV is set when the HI[0:31] and sign-bit LO[0] are not all the same.
Table II. (Word saturation operation mode).
*WMV *HIDDEN[0]
*WMV : WMV is set when the hidden bits and sign-bit HI[0] are not all the same.
W90221X version 0.6
0
0
1
1
The saturation instruction is intended to be used at the completion of a series of
0
1
1
0
05
0:5
6
The saturation condition and result depend on operation type of halfword or word
The cmplt completer c specifies the saturation mode on halfword or word
0
1
0
1
r2
6:10
5
0
1
0
1
SAT, cmplt, t
r1
11:15
5
No change
64
No change
64
~
16:18
0000_0000_7FFF_FFFF
No change
No change
64
64
FFFF_FFFF_8000_0000
3
c
7FFF_FFFF_FFFF_FFFF
8000 _0000 _0000 _0000
19
1
1
20
1
16
21:25
~
5
SAT
t
26
1
27:31
5
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