什么是DSP内存双映射

2万 · 2015-9-10 21:03

TM320F28027的内存图，此DSP是片上32K FLASH, 和片上6K RAM。
现在有个问题搞不明白，如图上的红框框，有两个L0 SARAM (4K x 16) 的 Dual Mapped空间，字面意思是双映射空间，但这个具体是什么意思，怎么理解呢？
这两个是随便用的还是怎么？实在是不明白，求帮忙解答！！！

1万 · 2015-9-10 21:04

L0与L1是镜像关系，具体用哪个要看CMD文件下面是CCS自带CMD的部分
从中看到它用了0x00 8000 – 0x00 8FFF的空间，那么0x3F 8000 – 0x3F 8FFF这个还能不能用？当然可以，但容量还是4Kx16，因为这两部分地址空间是重叠的，所以分配内存空间时要小心，不要重了。

MEMORY
{
PAGE 0: /* Program Memory */
         /* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE1 for data allocation */

PRAML0    : origin = 0x008000, length = 0x000800    /* on-chip RAM block L0 */
OTP       : origin = 0x3D7800, length = 0x000400    /* on-chip OTP */
FLASHD    : origin = 0x3F0000, length = 0x002000    /* on-chip FLASH */
FLASHC    : origin = 0x3F2000, length = 0x002000    /* on-chip FLASH */
FLASHA    : origin = 0x3F6000, length = 0x001F80    /* on-chip FLASH */
CSM_RSVD : origin = 0x3F7F80, length = 0x000076    /* Part of FLASHA.  Program with all 0x0000 when CSM is in use. */
BEGIN    : origin = 0x3F7FF6, length = 0x000002    /* Part of FLASHA.  Used for "boot to Flash" bootloader mode. */
CSM_PWL_P0  : origin = 0x3F7FF8, length = 0x000008    /* Part of FLASHA.  CSM password locations in FLASHA */

IQTABLES : origin = 0x3FE000, length = 0x000B50    /* IQ Math Tables in Boot ROM */
IQTABLES2 : origin = 0x3FEB50, length = 0x00008C    /* IQ Math Tables in Boot ROM */
IQTABLES3 : origin = 0x3FEBDC, length = 0x0000AA       /* IQ Math Tables in Boot ROM */

ROM       : origin = 0x3FF27C, length = 0x000D44    /* Boot ROM */
RESET    : origin = 0x3FFFC0, length = 0x000002    /* part of boot ROM  */
VECTORS    : origin = 0x3FFFC2, length = 0x00003E    /* part of boot ROM  */

PAGE 1 : /* Data Memory */
         /* Memory (RAM/FLASH/OTP) blocks can be moved to PAGE0 for program allocation */
         /* Registers remain on PAGE1                                                 */

BOOT_RSVD : origin = 0x000000, length = 0x000050    /* Part of M0, BOOT rom will use this for stack */
RAMM0    : origin = 0x000050, length = 0x0003B0    /* on-chip RAM block M0 */
RAMM1    : origin = 0x000400, length = 0x000400    /* on-chip RAM block M1 */
DRAML0    : origin = 0x008800, length = 0x000800    /* on-chip RAM block L0 */
FLASHB    : origin = 0x3F4000, length = 0x002000    /* on-chip FLASH */
}