C251 User's Guide

Tiny Model

In the Tiny memory model, all variables, by default, reside in the internal data memory of the 251 system - as if they were declared explicitly using the data memory type specifier.)

In this memory model, the variable and pointer access is very efficient. The default pointers size is just 2 bytes and represents pointers to near memory. Constants are placed in NCONST memory class. Using the HOLD directive, you can direct variables above a specific object size to other memory areas.

Typically, if the linker/locator is configured to overlay variables in the internal data memory, the Tiny model is the best model to use.