S3C72P9 datasheet(17/225 Pages) SAMSUNG

Part #	S3C72P9

Description	SINGLE-CHIP MICROCONTROLLER HAS BEEN DESIGNED FOR HIGH PERFORMANCE USING

PDF	225 Pages

Scroll/Zoom	100%

Manufacturer	SAMSUNG [Samsung semiconductor]

Direct Link	http://www.samsung.com/Products/Semiconductor

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17 / 225 page

S3C72P9/P72P9 (Preliminary Spec)

ADDRESS SPACES

2-5

INSTRUCTION REFERENCE AREA

Using 1-byte REF instructions, you can easily reference instructions with larger byte sizes that are stored in ad-

dresses 0020H–007FH of program memory. This 96-byte area is called the REF instruction reference area, or

look-up table. Locations in the REF look-up table may contain two 1-byte instructions, one 2-byte instruction, or

one 3-byte instruction such as a JP (jump) or CALL. The starting address of the instruction you are referencing

must always be an even number. To reference a JP or CALL instruction, it must be written to the reference area

in a two-byte format: for JP, this format is TJP; for CALL, it is TCALL. In summary, there are three ways to the

REF instruction:

By using REF instructions you can execute instructions larger than one byte. In summary, there are three ways

you can use the REF instruction:

— Using the 1-byte REF instruction to execute one 2-byte or two 1-byte instructions,

— Branching to any location by referencing a branch instruction stored in the look-up table,

— Calling subroutines at any location by referencing a call instruction stored in the look-up table.

S3C72P9 Datasheet(PDF) 17 Page - Samsung semiconductor