Paged memory for MC9S08AC128

[preetuabraham]

I have a PRM file for MC9S08AC128 for which I am not using Paged Memory Concept.I would like to know whether the memory allocation will be fine for data and code .Also I have only a single pragma statement # pragma DATA_SEG MySeg for some of the gloval variables in a single .c file and for rest it is # pragma DATA_SEG Default in the same file .Whether it is required to use the Paged memory concept .Also in the map file generated ,only few of the variables use the  PPAGE_2 ,rest use ROM,PAGE0,ROM1.

SEGMENTS /* Here all RAM/ROM areas of the device are listed. Used in PLACEMENT below. */
    MY_STK                   =  NO_INIT      0x15FF TO 0x17FF;
    RAM1                     =  READ_WRITE   0x0080 TO 0x01FF;
    RAMSEG                   =  READ_WRITE   0x0200  TO 0x0370;
    RAM2                     =  READ_WRITE   0x0372 TO 0x15FE;
    RAM3                     =  READ_WRITE   0x1870 TO 0x20EF;
    ROM                      =  READ_ONLY    0x20F0 TO 0x7FFF;
    ROM1                     =  READ_ONLY    0xC000 TO 0xFF9B;
    /* banked FLASH ROM */
    PPAGE_0                  =  READ_ONLY    0x008000 TO 0x00A0EF; /* PAGE partially contained in ROM segment */
    PPAGE_2                  =  READ_ONLY    0x028000 TO 0x02BFFF;
    PPAGE_4                  =  READ_ONLY    0x048000 TO 0x04BFFF;
    PPAGE_5                  =  READ_ONLY    0x058000 TO 0x05BFFF;
    PPAGE_6                  =  READ_ONLY    0x068000 TO 0x06BFFF;
    PPAGE_7                  =  READ_ONLY    0x078000 TO 0x07BFFF;
END

PLACEMENT /* Here all predefined and user segments are placed into the SEGMENTS defined above. */
    MySeg                      INTO  RAM1;
    DEFAULT_RAM                   INTO  RAM2,RAM3;
    DEFAULT_ROM, ROM_VAR, STRINGS INTO  ROM,PPAGE_0,ROM1,PPAGE_2,PPAGE_4,PPAGE_5,PPAGE_6,PPAGE_7; /* See compiler option -OnB=b. */
    //PAGED_ROM                      INTO  PPAGE_0,ROM1,PPAGE_2,PPAGE_4,PPAGE_5,PPAGE_6,PPAGE_7;    
   SSTACK                        INTO  MY_STK;

END

STACKSIZE 0x200

[ZhangJennie]

hi,

according to memory map, 0x10000 to 0x17fff is linear address for page4 and page5.

when use linear address mode, this range of memory address is 0x10000 to 0x17fff; if use page memory mode, the same memory is (0x048000 TO 0x04BFFF, and 0x058000 TO 0x05BFFF); user must choose one mode of them.

in banked memory mode, paged memory can be used for allocating code. code(function )  is inherently accessed by __far.  you needn't use #pragma for it.

however from what i am understanding linear address is only for data access. so you can't define all of the flash memory in linear address mode in prm file. code(function) must use paged and non-paged memory. data access can use linear address. see two demo code in an3730

Have a great day,
Jennie Zhang

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[preetuabraham]

Hi Zhang,

Whether the  memory range 0x10000 to 0x17fff is part of Paged memory and to use this I have to use banked memory model  or can use small memory model with MMU ?

[preetuabraham]

Hi Zhang,

  For the above PRM file, memory range 0x10000 to 0x17fff is not mentioned ,Whether we can use part of paged memory model or as part of small memory model

Since for the calcualtion of CRC ,While reading s-record data for 0x10000 to 0x17fff ,it is nto able to calcualte CRC

So for the above PRM ,whetehr I can modify as following for the Flash memory and I need small meory after 0xffff

ROM                      =  READ_ONLY    0x20F0 TO 0x7FFF;

    ROM1                     =  READ_ONLY    0xC000 TO 0xFF9B;

    /* banked FLASH ROM */

    PPAGE_0                  =  READ_ONLY    0x008000 TO 0x00A0EF; /* PAGE partially contained in ROM segment */

   PPAGE_1                   =  READ_ONLY    0x10000 TO 0x17fff

and under SEGMENTS section

    DEFAULT_ROM, ROM_VAR, STRINGS INTO  ROM,PPAGE_0,ROM1,PPAGE_1;

[ZhangJennie · Accepted solution]

Hi,

if the non-paged memory size is enough for your code, you needn't use paged memory. otherwise, it's necessary to use paged memory.

when use paged memory,  we need choose banked memory model:

we have an3730, an3730sw covered this topic. see:

http://cache.nxp.com/files/microcontrollers/doc/app_note/AN3730.pdf?fsrch=1&sr=2&pageNum=1

Software to accompany AN3730

can this help you?

Have a great day,
Jennie Zhang

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[preetuabraham]

Hi Zhang,

  For the above PRM file, memory range 0x10000 to 0x17fff is not mentioned ,Whether we can use part of paged memory model or as part of small memory model

Since for the calcualtion of CRC ,While reading s-record data for 0x10000 to 0x17fff ,it is nto able to calcualte CRC

So for the above PRM ,whetehr I can modify as following for the Flash memory and I need small meory after 0xffff

ROM                      =  READ_ONLY    0x20F0 TO 0x7FFF;

    ROM1                     =  READ_ONLY    0xC000 TO 0xFF9B;

    /* banked FLASH ROM */

    PPAGE_0                  =  READ_ONLY    0x008000 TO 0x00A0EF; /* PAGE partially contained in ROM segment */

   PPAGE_1                   =  READ_ONLY    0x10000 TO 0x17fff

and under SEGMENTS section

    DEFAULT_ROM, ROM_VAR, STRINGS INTO  ROM,PPAGE_0,ROM1,PPAGE_1;

[preetuabraham]

Thanks Jennie for that information

After usign the Banked memory ,software uses some of the section PPAGE2 from the PRM file given above,but

whether for those variables which are getting allocation in PPAGE2 I have to use # pragma statement  for the memory to get allocated correctly. Also since those variables are getting allocated in PPAGE 2 ,in the above PRM File I have to move PPAGE2 to PAGED_ROM from DEFAULT_ROM and use pragma statement for PAGED_ROM.What exactly PAGED_ROM means

See the allocation in map file from PAGED_ROM

*********************************************************************************************
SECTION-ALLOCATION SECTION
Section Name                    Size  Type     From       To       Segment
---------------------------------------------------------------------------------------------
MySeg                            301   R/W       0x80      0x1AC   RAM1
.data                            855   R/W      0x372      0x6C8   RAM2
.text                          23594     R     0x2129     0x7D52   ROM
.rodata                         9203     R     0xD884     0xFC76   ROM1
.rodata1                           1     R     0xFC77     0xFC77   ROM1
.stack                           512   N/I     0x15FF     0x17FE   MY_STK
.abs_section_200                  40   N/I      0x200      0x227   .absSeg77
.abs_section_228                  40   N/I      0x228      0x24F   .absSeg78
.abs_section_250                  80   N/I      0x250      0x29F   .absSeg2
.abs_section_2a0                  80   N/I      0x2A0      0x2EF   .absSeg3
.abs_section_2f0                 128   N/I      0x2F0      0x36F   .absSeg4
.abs_section_ffbd                  1     R     0xFFBD     0xFFBD   .absSeg5
.abs_section_ffbf                  1     R     0xFFBF     0xFFBF   .absSeg6
.abs_section_ffcc                150     R     0xFFCC    0x10061   .absSeg8
.abs_section_0                     1   N/I        0x0        0x0   .absSeg9
.abs_section_1                     1   N/I        0x1        0x1   .absSeg10
.abs_section_2                     1   N/I        0x2        0x2   .absSeg11
.abs_section_3                     1   N/I        0x3        0x3   .absSeg12
.abs_section_4                     1   N/I        0x4        0x4   .absSeg13
.abs_section_5                     1   N/I        0x5        0x5   .absSeg14
.abs_section_6                     1   N/I        0x6        0x6   .absSeg15
.abs_section_7                     1   N/I        0x7        0x7   .absSeg16
.abs_section_8                     1   N/I        0x8        0x8   .absSeg17
.abs_section_9                     1   N/I        0x9        0x9   .absSeg18
.abs_section_a                     1   N/I        0xA        0xA   .absSeg19
.abs_section_b                     1   N/I        0xB        0xB   .absSeg20
.abs_section_c                     1   N/I        0xC        0xC   .absSeg21
.abs_section_d                     1   N/I        0xD        0xD   .absSeg22
.abs_section_1c                    1   N/I       0x1C       0x1C   .absSeg23
.abs_section_20                    1   N/I       0x20       0x20   .absSeg24
.abs_section_25                    1   N/I       0x25       0x25   .absSeg25
.abs_section_28                    1   N/I       0x28       0x28   .absSeg26
.abs_section_2b                    1   N/I       0x2B       0x2B   .absSeg27
.abs_section_3a                    1   N/I       0x3A       0x3A   .absSeg28
.abs_section_3b                    1   N/I       0x3B       0x3B   .absSeg29
.abs_section_3c                    1   N/I       0x3C       0x3C   .absSeg30
.abs_section_3d                    1   N/I       0x3D       0x3D   .absSeg31
.abs_section_3e                    1   N/I       0x3E       0x3E   .absSeg32
.abs_section_3f                    1   N/I       0x3F       0x3F   .absSeg33
.abs_section_48                    1   N/I       0x48       0x48   .absSeg34
.abs_section_49                    1   N/I       0x49       0x49   .absSeg35
.abs_section_4a                    1   N/I       0x4A       0x4A   .absSeg36
.abs_section_4b                    1   N/I       0x4B       0x4B   .absSeg37
.abs_section_50                    1   N/I       0x50       0x50   .absSeg38
.abs_section_51                    1   N/I       0x51       0x51   .absSeg39
.abs_section_52                    1   N/I       0x52       0x52   .absSeg40
.abs_section_53                    1   N/I       0x53       0x53   .absSeg41
.abs_section_55                    1   N/I       0x55       0x55   .absSeg42
.abs_section_58                    1   N/I       0x58       0x58   .absSeg43
.abs_section_59                    1   N/I       0x59       0x59   .absSeg44
.abs_section_5a                    1   N/I       0x5A       0x5A   .absSeg45
.abs_section_5b                    1   N/I       0x5B       0x5B   .absSeg46
.abs_section_5c                    1   N/I       0x5C       0x5C   .absSeg47
.abs_section_1800                  1   N/I     0x1800     0x1800   .absSeg48
.abs_section_1802                  1   N/I     0x1802     0x1802   .absSeg49
.abs_section_1840                  1   N/I     0x1840     0x1840   .absSeg50
.abs_section_1841                  1   N/I     0x1841     0x1841   .absSeg51
.abs_section_1844                  1   N/I     0x1844     0x1844   .absSeg52
.abs_section_1845                  1   N/I     0x1845     0x1845   .absSeg53
.abs_section_1848                  1   N/I     0x1848     0x1848   .absSeg54
.abs_section_1849                  1   N/I     0x1849     0x1849   .absSeg55
.abs_section_184c                  1   N/I     0x184C     0x184C   .absSeg56
.abs_section_184d                  1   N/I     0x184D     0x184D   .absSeg57
.abs_section_1850                  1   N/I     0x1850     0x1850   .absSeg58
.abs_section_1851                  1   N/I     0x1851     0x1851   .absSeg59
.abs_section_1854                  1   N/I     0x1854     0x1854   .absSeg60
.abs_section_1855                  1   N/I     0x1855     0x1855   .absSeg61
.abs_section_1858                  1   N/I     0x1858     0x1858   .absSeg62
.abs_section_1859                  1   N/I     0x1859     0x1859   .absSeg63
.abs_section_21                    2   N/I       0x21       0x22   .absSeg64
.abs_section_22                    2   N/I       0x22       0x23   .absSeg65
.abs_section_23                    2   N/I       0x23       0x24   .absSeg66
.abs_section_24                    2   N/I       0x24       0x25   .absSeg67
.abs_section_26                    2   N/I       0x26       0x27   .absSeg68
.abs_section_27                    2   N/I       0x27       0x28   .absSeg69
.abs_section_29                    2   N/I       0x29       0x2A   .absSeg70
.abs_section_2a                    2   N/I       0x2A       0x2B   .absSeg71
.abs_section_2c                    2   N/I       0x2C       0x2D   .absSeg72
.abs_section_2d                    2   N/I       0x2D       0x2E   .absSeg73
.abs_section_38                    1   N/I       0x38       0x38   .absSeg74
.abs_section_39                    1   N/I       0x39       0x39   .absSeg75
.abs_section_371                   1   N/I      0x371      0x371   .absSeg76
.abs_section_2bfc4                 8   N/I    0x2BFC4    0x2BFCB   .absSeg79
.abs_section_370                   1   N/I      0x370      0x370   .absSeg80
.abs_section_2bfc0                 4   N/I    0x2BFC0    0x2BFC3   .absSeg81
.bss                             357   R/W      0x6C9      0x82D   RAM2
.startData                        38     R     0x2103     0x2128   ROM
.init                             19     R     0x20F0     0x2102   ROM
.common                         1382   R/W      0x82E      0xD93   RAM2
NON_BANKED                       784     R     0xFC78     0xFF87   ROM1
.copy                            868     R    0x280BA    0x2841D   PPAGE_2
PPAGE_0_82                     16127     R     0x8000     0xBEFE   PPAGE_0
ROM1_83                         6276     R     0xC000     0xD883   ROM1
PPAGE_2_84                       186     R    0x28000    0x280B9   PPAGE_2

Summary of section sizes per section type:
READ_ONLY (R):        DFA0 (dec:    57248)
READ_WRITE (R/W):      B4F (dec:     2895)
NO_INIT (N/I):         3CB (dec:      971)

[ZhangJennie]

HI,

If you use banked memory model,

code(function )  is inherently accessed by __far.  you needn't use #pragma for it.

while data is accessed by __near. thus you need use #pragma to define variable in paged memory.

Have a great day,
Jennie Zhang

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