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SYNTAX      DIRECT   [<LABEL>] SUBH <dma>
            INDIRECT [<LABEL>] SUBH {ind}[,<next ARP>]

OPERANDS    0 . dma . 127; 0 . next ARP . 7.

EXECUTION   (PC) + 1 . PC
            (ACC) - [(dma) * 2 ^ 16] . ACC
            Affects OV; affected by OVM.
            Affects C (TMS320C25).

DESCRIPTION The contents of the addressed data memory location are
            subtracted from the upper 16 bits of the accumulator. The 16
            low-order bits of the accumulator are unaffected. The result
            is stored in the accumulator. The carry bit C on the TMS320C25
            is reset if the result of the subtraction generates a borrow;
            otherwise, C is unaffected.

            The SUBH instruction can be used in performing 32-bit
            arithmetic.

WORDS       1

ENCODING    15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            +-----------------------------------------------+
            |0  1  0  0  0  1  0  0| 0| data memory address | DIRECT
            +-----------------------------------------------+

            15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            +-----------------------------------------------+
            |0  1  0  0  0  1  0  0| 1| see indirect fields | INDIRECT
            +-----------------------------------------------+

CYCLES

            +------------------------------------------------+
            |    Cycle Timings for a Single Instruction      |
            |------------------------------------------------|
            | PI/DI | PI/DE | PE/DI | PE/DE  | PR/DI | PR/DE |
            |-------+-------+-------+--------+-------+-------|
      '20   |   1   |  2+d  |  1+p  | 2+d+p  |   -   |   -   |
            |-------+-------+-------+--------+-------+-------|
     'C25   |   1   |  2+d  |  1+p  | 2+d+p  |   1   |  2+d  |
            |------------------------------------------------|
            |    Cycle Timings for a Repeat Instruction      |
            |------------------------------------------------|
      '20   |   n   | 2n+nd |  n+p  | 2n+nd+p|   -   |   -   |
            |-------+-------+-------+--------+-------+-------|
     'C25   |   n   |1+n+nd |  n+p  |1+n+nd+p|   n   |1+n+nd |
            +------------------------------------------------+



EXAMPLE     SUBH  DAT33       (DP = 6)
            or
            SUBH  *           If current auxiliary register contains 801.

                  BEFORE                AFTER

            dm801     >6         dm801    >11
            ACC X >A0013         ACC 1 >60013
                C                    C