Chapter 2. Program Organization18 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C2.1.6 Local DataEach block or UDFB in a block-structured program has an associated local data block. _MAIN’s datablock memory is referenced by %P; all other data block memories are referenced by %L.The size of the data block is dependent on the highest reference in its block for %L and in all blocksfor %P.Figure 8: Relationship of %L & %P to Program BlocksAll blocks within the program can use data associated with the _MAIN block (%P). Blocks and UDFBscan use their own %L data as well as the %P data that is available to all blocks. The _MAIN blockcannot use %L.External blocks and parameterized blocks can use the Local Data (%L) of their calling block as well asthe %P data of the _MAIN block. If a parameterized block or external block is called by MAIN, all %Lreferences in the parameterized block or external block will actually be references to corresponding%P references (for example, %L0005 = %P0005). In addition to inheriting the Local Data of theircalling blocks, parameterized blocks and external blocks inherit the FST_EXE status of their callingblocks.PSB 1orEB 1BLOCK1data%P_MAINBlockdata%LInherits as %LPSB 2orEB 2Inherits as %LFigure 9: Local Data (%L) Usage by Program BlocksBlock2Block3Block4data%LData%LData%Ldata%P_MAINblock
