Freescale Semiconductor SC140 specifications DSP Core Instruction Set

Models: SC140

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DSP Core Instruction Set

Hh: High register expansion encoding for AGU execution unit 0. This includes all AGU and BMU instructions. R0-7 registers are expanded up to R0-15.

The two bits Hh controls the expansion of R0-R7 registers to R8-R15 registers in one or two AGU instruction’s operands according to the following rules:

The H bit is used for all of the operands from the types:

-Rn operand defined with RRR field (e.g. Rn in MOVE like instruction, or ADDA instructions, EA or ea in MOVE like instructions).

-Rx operand defined with RRRR field.

-Df operand defined with hhh field of MOVE.L Df,C4 and MOVE.L C4.Df instructions. The h bit is used for all the operands other then the above.

The expansion encoding have no effect if the register decoded in the instruction is not R0-R7 (e.g. SP in RRRR field for Rx decoding).

Fields representing multiple registers (used in some MOVE-like instructns) are affected together. For example, the register pair encoding for D0:D1 can be expanded to D8:D9 (not each register independently).

Note that Rr register in (Rn+Rr) addressing mode, is limited to R0-R7 and thus not effected by both H and h bits.

Tt: The same as Hh, but for AGU execution unit 1.

Note the special position of the T bit (bit 8 in the second word).

SC140 DSP Core Reference Manual

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Page 325
Image 325
Freescale Semiconductor SC140 specifications DSP Core Instruction Set