ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Instruction Details
A8.6.255 USAT
Unsigned Saturate saturates an optionally-shifted signed value to a selected unsigned range.
The Q flag is set if the operation saturates.
Encoding T1 ARMv6T2, ARMv7
USAT ,#,{,}
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 1 0 (0) 1 1 1 0 sh 0 Rn 0 imm3 Rd imm2(0) sat_imm
if sh == ‘1’ && (imm3:imm2) == ‘00000’ then SEE USAT16;
d = UInt(Rd); n = UInt(Rn); saturate_to = UInt(sat_imm);
(shift_t, shift_n) = DecodeImmShift(sh:’0’, imm3:imm2);
if BadReg(d) || BadReg(n) then UNPREDICTABLE;
Encoding A1 ARMv6*, ARMv7
USAT ,#,{,}
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
cond 0 1 1 0 1 1 1 sat_imm Rd imm5 sh 0 1 Rn
d = UInt(Rd); n = UInt(Rn); saturate_to = UInt(sat_imm);
(shift_t, shift_n) = DecodeImmShift(sh:’0’, imm5);
if d == 15 || n == 15 then UNPREDICTABLE;
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