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Section 3 DSP Operation
Rev. 4.00 Sep. 14, 2005 Page 110 of 982
REJ09B0023-0400
In this arithmetic shift operation, all bits of the source 1 and destination operands are activated.
The shift amount is specified by the source 2 operand as an integer data. The source 2 operand can
be specified by either a register or immediate operand. The available shift range is from
–32 to +32. Here, a negative value means the right shift, and a positive value means the left shift.
It is possible for any source 2 operand to specify from –64 to +63 but the result is unknown if an
invalid shift value is specified. In case of a shift with an immediate operand instruction, the source
1 operand must be the same register as the destination's. This operation is executed in the DSP
stage, as shown in figure 3.2 as well as in fixed-point operations. The DSP stage is the same stage
as the MA stage in which memory access is performed.
Every time an arithmetic shift operation is executed, the DC, N, Z, V, and GT bits in DSR are
basically updated in accordance with the operation result. In case of a conditional operation, they
are not updated even though the specified condition is true and the operation is executed. In case
of an unconditional operation, they are always updated in accordance with the operation result.
The definition of the DC bit is selected by the CS[2:0] (condition selection) bits in DSR. The DC
bit result is:
1. Carry or Borrow Mode: CS[2:0] = 000
The DC bit indicates the last shifted out data as the operation result.
2. Negative Value Mode: CS[2:0] = 001
The DC bit is set when the operation result is a negative value, and cleared when the operation
result is zero or a positive value.
3. Zero Value Mode: CS[2:0] = 010
The DC bit is set when the operation result is zero; otherwise it is cleared.
4. Overflow Mode: CS[2:0] = 011
The DC bit is always cleared.
5. Signed Greater Than Mode: CS[2:0] = 100
The DC bit is always cleared.
6. Signed Greater Than or Equal Mode: CS[2:0] = 101
The DC bit is always cleared.
The N bit always indicates the same state as the DC bit set in negative value mode by the CS[2:0]
bits. See the negative value mode part above. The Z bit always indicates the same state as the DC
bit set in zero value mode by the CS[2:0] bits. See the zero value mode part above. The V bit
always indicates the same state as the DC bit set in overflow mode by the CS[2:0] bits. See the
overflow mode part above. The GT bit always indicates the same state as the DC bit set in signed
greater than mode by the CS[2:0] bits. See the signed greater than mode part above.
Summary of Contents for HD6417641
Page 2: ...Rev 4 00 Sep 14 2005 Page ii of l...
Page 7: ...Rev 4 00 Sep 14 2005 Page vii of l...
Page 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
Page 12: ...Rev 4 00 Sep 14 2005 Page xii of l...
Page 28: ...Rev 4 00 Sep 14 2005 Page xxviii of l...
Page 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Page 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Page 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Page 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Page 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Page 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Page 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Page 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Page 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Page 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Page 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Page 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Page 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
Page 1032: ...Rev 4 00 Sep 14 2005 Page 982 of 982 REJ09B0023 0400 X X Y data addressing 52 X Y memory 193...
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