Techniques have been developed to introduce processor core functional pattern tests into a memory space addressable by at least one processor core of an integrated circuit. In general, such functional pattern tests can include both instruction sequences and data patterns and, in some embodiments in accordance with the present invention, are introduced (at least in part) into on-chip cache memory using facilities of an on-chip loader. Instruction opcodes used in functional test sequences may be efficiently introduced into a plurality of target locations in memory (e.g., at locations corresponding to multiple interrupt handlers or at locations from which a multiplicity of cores execute their functional tests) using facilities of the on-chip loader. In some embodiments, instruction selections together with a base address, extent and stride indications may be used to direct operation of the on-chip loader. Likewise, data patterns used in the functional test sequences may be specified as a data pattern selection together with base address, extent and optional stride indications and introduced into a plurality of target memory locations using facilities of the on-chip loader. In some embodiments, other forms or encodings of directives may be used.