Hi,

I am using Keil uVision 2. There is a feature "Performance analyser" which can monitor the usage time of all the functions.

Do they have something which do the same thing for my variables (xdata, idata)?

I had created many xdata variables, and I am running out of code space. I had tried to change some xdata variables to idata. I manage to get back some code space.

I would want to shift the very frequently used variables and set them as idata. Is there anyway to tell which variables is most frequently used?

Below is my M51 RAM usage

----------------------------------------------------
INPUT MODULES INCLUDED:
.objSTARTUP.obj (?C_STARTUP)
.objMAIN.obj (MAIN)
.objsys.obj (SYS)
.objmot.obj (MOT)
.objcmd.obj (CMD)
.objuart.obj (UART)
.objmem.obj (MEM)
.objmemdata.obj (MEMDATA)
.objtim.obj (TIM)
.objuart2.obj (UART2)
.objrx2iaplib.obj (RX2IAPLIB)
.objupg.obj (UPG)
C:KEILC51LIBC51S.LIB (?C_INIT)
C:KEILC51LIBC51S.LIB (?C?ILDPTR)
C:KEILC51LIBC51S.LIB (?C?ISTPTR)
C:KEILC51LIBC51S.LIB (?C?OFFXADD)
C:KEILC51LIBC51S.LIB (?C?PLDIDATA)
C:KEILC51LIBC51S.LIB (?C?PSTIDATA)
C:KEILC51LIBC51S.LIB (?C?ICALL)

...

* * * * * * * D A T A M E M O R Y * * * * * * *
REG 0000H 0008H ABSOLUTE "REG BANK 0"
DATA 0008H 0007H UNIT ?DT?MOT
DATA 000FH 0007H UNIT ?DT?TIM
DATA 0016H 0005H UNIT ?DT?CMD
DATA 001BH 0003H UNIT ?DT?UART2
DATA 001EH 0002H UNIT ?DT?SYS
BIT 0020H.0 0000H.3 UNIT ?BI?SYS
BIT 0020H.3 0000H.2 UNIT ?BI?MOT
BIT 0020H.5 0000H.1 UNIT ?BI?UART
BIT 0020H.6 0000H.1 UNIT ?BI?TIM
BIT 0020H.7 0000H.1 UNIT _BIT_GROUP_
DATA 0021H 0003H UNIT _DATA_GROUP_
IDATA 0024H 0001H UNIT ?STACK

* * * * * * * X D A T A M E M O R Y * * * * * * *
XDATA 0000H 0086H UNIT ?XD?UPG
XDATA 0086H 00CFH UNIT ?XD?UART2
XDATA 0155H 00CCH UNIT ?XD?UART
XDATA 0221H 0082H UNIT ?XD?MEM
XDATA 02A3H 0004H UNIT ?XD?SYS
XDATA 02A7H 0004H UNIT ?XD?CMD
XDATA 02ABH 0002H UNIT _XDATA_GROUP_
XDATA 02ADH 0001H UNIT ?XD?MOT