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Section 2 CPU
Rev. 4.00 Sep. 14, 2005 Page 96 of 982
REJ09B0023-0400
Table 2.32 DC Bit Update Definitions
CS [2:0] Condition Mode
Description
0 0 0 Carry
or
borrow
mode
The DC bit is set if an ALU arithmetic operation generates a carry
or borrow, and is cleared otherwise.
When a PSHA or PSHL shift instruction is executed, the last bit
data shifted out is copied into the DC bit.
When an ALU logical operation is executed, the DC bit is always
cleared.
0 0 1 Negative
value
mode
When an ALU or shift (PSHA) arithmetic operation is executed,
the MSB of the result, including the guard bits, is copied into the
DC bit.
When an ALU or shift (PSHL) logical operation is executed, the
MSB of the result, excluding the guard bits, is copied into the DC
bit.
0 1 0 Zero value mode
The DC bit is set if the result of an ALU or shift operation is all-
zeros, and is cleared otherwise.
0 1 1 Overflow mode
The DC bit is set if the result of an ALU or shift (PSHA) arithmetic
operation exceeds the destination register range, excluding the
guard bits, and is cleared otherwise.
When an ALU or shift (PSHL) logical operation is executed, the
DC bit is always cleared.
1 0 0 Signed
greater-than
mode
This mode is similar to signed greater-or-equal mode, but DC is
cleared if the result is all-zeros.
DC = ~{(negative value ^ over-range) | zero value};
In case of arithmetic operation
DC = 0; In case of logical operation
1 0 1 Signed
greater-or-
equal mode
If the result of an ALU or shift (PSHA) arithmetic operation
exceeds the destination register range, including the guard bits
("over-range"), the definition is the same as in negative value
mode. If the result is not over-range, the definition is the opposite
of that in negative value mode.
When an ALU or shift (PSHL) logical operation is executed, the
DC bit is always cleared.
DC = ~(negative value ^ over-range);
In case of arithmetic operation
DC = 0 ; In case of logical operation
1 1 0 Reserved
1 1 1 Reserved
Содержание HD6417641
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Страница 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
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Страница 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Страница 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Страница 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Страница 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Страница 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Страница 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Страница 500: ...Section 13 Direct Memory Access Controller DMAC Rev 4 00 Sep 14 2005 Page 450 of 982 REJ09B0023 0400...
Страница 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Страница 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Страница 734: ...Section 18 Multi Function Timer Pulse Unit MTU Rev 4 00 Sep 14 2005 Page 684 of 982 REJ09B0023 0400...
Страница 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Страница 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Страница 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Страница 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Страница 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
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