The memory map in the CPM2A is predefined as outlined in section 5 of the manual.
IR MEMORY
IR Memory is used for inputs, outputs and work bits.
Inputs are mapped to 10 Words 000 through 009 OR 160 Bits 00000-00915.
Outputs are mapped to the next 10 words of IR memory 010 through 019 OR 160 Bits 01000-01915.
Work bits are located in words 020-049 and 200-227
As you add expansion I/O modules they consume a specific area in IR memory. Any IR I/O areas between 000-019 not consumed by physical I/O modules can also used can be used as internal work bits.
TC MEMORY
T[imer]/C[ounter]memory area. There can be a total of 256 timers or counters. Be warned that timers and counters CANNOT share the same TC number. You must use a different TC number for every TIMER or COUNTER. [See Limitations in 7-15-1 in manual]
Addressing IR Memory.
Initially users get easily confused about how to address IR areas in their programs. You DO NOT use the IR prefix. You simply use the IR Number.
To use a bit address IR 00000 you can type "00000" OR "0" OR "0.0" they all point to the same IR memory location.
Likewise to use a bit address IR 00100 you can type "00100" OR "100" OR "1.0".
Hope this helps, good luck.