Zilog ZUSBOPTS Manual do Utilizador descarregar pdf (Página 348)

100

101

Program Configurations UM017105-0511

320

Zilog Developer Studio II – ZNEO™

User Manual

1. To set up this configuration, you must place the CODE segment in ERAM at run time

and EROM at load time. Do this by adding the following linker commands in the

Additional Linker Directives dialog box (see Additional Directives – see page 62):

change code=ERAM /* Run time CODE is in ERAM space */

copy code EROM /* Load time CODE is in EROM space */

define _low_code_copy = copy base of CODE

define _low_code = base of CODE

define _len_code = length of CODE

2. The linker COPY directive only designates the load addresses and the run-time

addresses for the segment. The actual copying of the segment must be performed by

the start-up code. For example if you are using the small model, copy and modify the

C startup provided in the installation under

src\boot\common\startupexs.asm,

rewriting the relevant section as follows:

;

; Copy CODE into ERAM

;

LEA R0,_low_code_copy

LEA R1,_low_code

LD R2,#_len_code+1

JP clab1

clab0:

LD.B R3,(R0++)

LD.B (R1++),R3

clab1:

DJNZ R2,clab0

XREF _low_code_copy:EROM

XREF _len_code:ERAM

XREF _low_code:ERAM

3. Finally, add your modified start-up module to your project. Select the Included in

Project

button in the Objects and Libraries page of the Project Settings dialog box

(see C Start-up Module

– see page 66) and also add the modified source code file to

your project using the Add Files command from the

Project menu.

Special Case: Partial Copy to ERAM

A special case of this configuration is when you want to copy program code from just one

C source file into ERAM, while retaining the rest of the code in EROM. This allows you

to gain the potential speed advantages of external RAM over external Flash for a specific

module. Perform the following steps:

1. Select the

Distinct Code Segment for Each Module checkbox in the Advanced

page in the

Project Settings dialog box (see page 59).

1 2 ... 343 344 345 346 347 348 349 350 351 352 353 ... 519 520

Comentários a estes Manuais

Sem comentários

Zilog ZUSBOPTS Manual do Utilizador Página 348

Comentários a estes Manuais

Manuais e produtos relacionados com Sensores Zilog ZUSBOPTS