Dear All: While I am studying *.M51 file, I discovered serveral unknown descriptions with which I need your help. Section: LINK MAP OF MODULE: .\obj\moonplus (MAIN) TYPE BASE LENGTH RELOCATION SEGMENT NAME ----------------------------------------------------- * * * * * * * D A T A M E M O R Y * * * * * * * REG 0000H 0008H ABSOLUTE "REG BANK 0" REG 0008H 0008H ABSOLUTE "REG BANK 1" REG 0010H 0008H ABSOLUTE "REG BANK 2" REG 0018H 0008H ABSOLUTE "REG BANK 3" BIT 0020H.0 0002H.2 UNIT _BIT_GROUP_ BIT 0022H.2 0000H.7 UNIT ?BI?MAIN BIT 0023H.1 0000H.6 UNIT ?BI?L1_5B BIT 0023H.7 0000H.6 UNIT ?BI?DOSFAT BIT 0024H.5 0000H.5 UNIT ?BI?SONY_LENS BIT 0025H.2 0000H.3 UNIT ?BI?UIFLOW BIT 0025H.5 0000H.3 UNIT ?BI?IQDEBUG BIT 0026H.0 0000H.2 UNIT ?BI?MCU BIT 0026H.2 0000H.2 UNIT ?BI?SKYLAR_SHIT BIT 0026H.4 0000H.2 UNIT ?BI?BUBU_3B BIT 0026H.6 0000H.1 UNIT ?BI?BULKOUT BIT 0026H.7 0000H.1 UNIT ?BI?L1_PREVIEW BIT 0027H.0 0000H.1 UNIT ?BI?DOSRW BIT 0027H.1 0000H.1 UNIT ?BI?MEMORY_RW?MCU BIT 0027H.2 0000H.1 UNIT ?BI?GOTOCURGAIN?BUBU_3B 0027H.3 0000H.5 *** GAP *** DATA 0028H 0018H UNIT _DATA_GROUP_ DATA 0040H 0009H UNIT ?DT?L1_ISP DATA 0049H 0002H UNIT ?DT?DOSFAT DATA 004BH 0002H UNIT ?DT?SMC_READREDUNDATA2SRAM?SMCHW533 DATA 004DH 0002H UNIT ?DT?BUBU_3B DATA 004FH 0001H UNIT ?DT?SMCCORE DATA 0050H 0004H ABSOLUTE DATA 0054H 0004H ABSOLUTE DATA 0058H 0004H ABSOLUTE DATA 005CH 0002H ABSOLUTE DATA 005EH 0008H UNIT ?DT?MAIN DATA 0066H 0001H UNIT ?DT?IQDEBUG IDATA 0067H 000CH UNIT ?ID?DOSRW IDATA 0073H 0006H UNIT ?ID?CTLSETUP IDATA 0079H 0004H UNIT ?ID?AVILIB IDATA 007DH 0004H UNIT ?ID?DOSFAT =================================================== In the "TYPE" column, what are the difference between "REG", "BIT", "DATA" and "IDATA" ? In the "RELOCATION" column, what are the meanings of "ABSOLUTE" and "UNIT" ? How do I control "GAP" segment? Any suggestion will be highly appreciated. Best, Yuncheng Lin (Eric)