Memory Requirements

Table of Contents

• Stack and Heap
• netlib Code Section
• Example linker command instructions
• Common Modules Code Section
• Code and Data Size

Stack and Heap

Minimum stack size should be 1024 words. Minimum heap size depends on configuration. By default 3500 words of heap are necessary, but up to 2500 words can optionally be placed into bss section when neccessary.


All other memories (buffers, etc.) are user-defined and application specific and may be allocated statically or dynamically.

netlib Code Section

The net.lib library uses two special code sections:

• .nettextfast
• .nettextslow

Performance critical functions are located in .nettextfast and should be mapped to fastest memory in the linker command file. .nettextslow can be linked to slower memory without noticeable performance penalties.

Example linker command instructions

Example linker command file: Refer to Example Linker Command File

Definition in application linker command file App.cmd:

#define NETSECFAST    RAML1
#define NETSECSLOW    POFFCHIP
SECTIONS
{
   /* link the fast netlib code to internal memory for maximum speed */
/*   .net_smc91c1x { -lnet.lib<smc91c1x.obj>(.nettextfast) } > PROG , PAGE = 0  */
/*   .net_memb     { -lnet.lib<memb.obj>(.nettextfast) }     > PROG , PAGE = 0  */
/*   .net_ip       { -lnet.lib<ip.obj>(.nettextfast) }       > PROG , PAGE = 0  */
/*   .net_socket   { -lnet.lib<socket.obj>(.nettextfast) }   > PROG , PAGE = 0 */
/*   .net_tcp      { -lnet.lib<tcp.obj>(.nettextfast) }      > PROG , PAGE = 0  */
/*   .net_udp      { -lnet.lib<udp.obj>(.nettextfast) }      > PROG , PAGE = 0  */

    .nettextfast > NETSECFAST , PAGE = 0  /* fast netlib code                           */
    .nettextslow > NETSECSLOW , PAGE = 0  /* slow netlib code                           */
}

#include "../../../Libs/Netlib/net.cmd" 

Memory assignment in netlib linker command file \Libs\Netlib\net.cmd by using previous definition:

    .nettextfast > NETSECFAST   /* fast netlib code                           */
    .nettextslow > NETSECSLOW   /* slow netlib code                           */

Common Modules Code Section

The Common Support Modules included with the Support SW can also be linked to external memory, since no time-critical function is defined within these modules. Use the following linker instruction to link these modules to external memory:

Definition in application linker command file App.cmd:

/* #define COMMONSECTIONS  RAML7 */
#define COMMONSECTIONS  POFFCHIP  /*  all common modules linked to external RAM */

SECTIONS
{
    /*------------------------------------------------------------------------*/
    /* Support functions                                                      */
    /*------------------------------------------------------------------------*/
    .uarttext    > COMMONSECTIONS ,PAGE = 0  /* UART code                              */
    .cprintftext > COMMONSECTIONS ,PAGE = 0  /* CPrintf section                        */
    .commontext  > COMMONSECTIONS ,PAGE = 0  /* common code                            */
}

Memory assignment in linker command file \Common\CommonSections.cmd by using previous definition:

SECTIONS
{
    /*------------------------------------------------------------------------*/
    /* Support functions                                                      */
    /*------------------------------------------------------------------------*/
    .uarttext    > COMMONSECTIONS   /* UART code                              */
    .cprintftext > COMMONSECTIONS   /* CPrintf section                        */
    .commontext  > COMMONSECTIONS   /* common code                            */
}

Code and Data Size

Required Code and Data size depends on used protocols and sockets:

CCS5.5, CGTools 16.9.10, netlib 2.92.03
Code Size:
    Adapter + MAC + PHY             3568 words
    ARP                             1031 words
    Sockets                         3514 words
    IP                               711 words
    ICMP                             457 words
    UDP                              691 words
    TCP                             4356 words
    DNS                              418 words
    DHCP                            1472 words

Stack Size:                         1024 words
Heap Size:
    Adapter/PHY                      118 words
    per UDP/ICMP Socket              256 words
    per TCP Socket                    82 words

optional on heap or static
    Socket send FIFO                 768 words
    TCP send seq numbers            1152 words
    ARP list entries                 540 words