Words, Cycles – Texas Instruments TMS320C2XX User Manual

Page 169

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How To Use the Instruction Descriptions

7-16

7.2.7

Words

The words category specifies the number of memory words (one or two) re-
quired to store the instruction. When the number of words depends on the ad-
dressing mode used for an instruction, the words category specifies which ad-
dressing modes require one word and which require two words.

7.2.8

Cycles

The cycles category of each instruction description contains tables showing
the number of processor machine cycles (CLKOUT1 periods) required for the
instruction to execute in a given memory configuration when executed as a
single instruction or when repeated with the RPT instruction. For example:

Cycles for a Single Instruction

Program

Operand

ROM

DARAM

SARAM

External

DARAM

1

1

1

1+p

SARAM

1

1

1

1+p

External

1+d

1+d

1+d

2+d+p

Cycles for a Repeat (RPT) Execution of an Instruction

Program

Operand

ROM

DARAM

SARAM

External

DARAM

n

n

n

n+p

SARAM

n

n

n

n+p

External

n+nd

n+nd

n+nd

n+1+p+nd

The column headings in these tables indicate the program source location, de-
fined as follows:

ROM

The instruction executes from internal program ROM.

DARAM

The instruction executes from internal dual-access program RAM.

SARAM

The instruction executes from internal single-access program RAM.

External The instruction executes from external program memory.

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