X-Hacker.org- TMS320C2x DSP - syntax [<label>] sblk <constant>[,<shift>]

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SYNTAX      [<LABEL>] SBLK <constant>[,<shift>]

OPERANDS    16-bit constant
             0 . shift . 15 (defaults to 0)

EXECUTION   (PC) + 2 . PC
            (ACC) - [constant * 2 ^ shift] . ACC
            If SXM = 1, then -32768 . constant . 32767;
            If SXM = 0, then 0 . constant . 65535.
            Affects OV; affected by OVM and SXM.
            Affects C (TMS320C25).

DESCRIPTION The immediate field of the instruction is subtracted from the
            accumulator. The result replaces the accumulator contents. SXM
            determines whether the constant is treated as a signed two's-
            complement number or as an unsigned number. The shift count
            is optional and defaults to zero.

WORDS       2

ENCODING    15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            +-----------------------------------------------+
            |1  1  0  1|   shift   | 0  0  0  0  0  0  1  1 |
            |-----------------------------------------------|
            |                16-bit constant                |
            +-----------------------------------------------+

CYCLES

            +------------------------------------------------+
            |     Cycle Timings for a Single Instruction     |
            |------------------------------------------------|
            | PI/DI | PI/DE | PE/DI | PE/DE  | PR/DI | PR/DE |
            |-------+-------+-------+--------+-------+-------|
      '20   |   2   |   2   |  2+2p |  2+2p  |   -   |   -   |
            |-------+-------+-------+--------+-------+-------|
     'C25   |   2   |   2   |  2+2p |  2+2p  |   2   |   2   |
            |------------------------------------------------|
            |     Cycle Timings for a Repeat Instruction     |
            |------------------------------------------------|
      '20   |       not repeatable           |   -   |   -   |
            |------------------------------------------------|
     'C25   |                 not repeatable                 |
            +------------------------------------------------+



EXAMPLE     SBLK  5,12

                         BEFORE             AFTER

                  ACC X >3FC0EF     ACC 1 >3F70EF
                      C                 C

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