BL51: Writing Your Own Code Banking System

Information in this article applies to:

• C51 Version 5.50

QUESTION

How can I configure the linker so that it locates functions in different code banks but does not implement code banking? The reason is that I want to write my own code banking system.

ANSWER

You may use the code below as a dummy L51_BANK.A51 file as it contains the bare minimum for the linker to link a code banking project. Add this file to your project. You may then write whatever code you require or develop whatever system you need to implement your own code banking.

;--------------------------------------------------------
;  This file disables the bank switching of the BL51 Banked Linker/Locater
;  and allows code banking with own user routines.
;--------------------------------------------------------
;*********** Configuration Section ************
?B_NBANKS       EQU     16       ; Define max. Number of Banks
;                                ; the max. value for ?B_BANKS is 32
;
; Dummy Definitions
; -----------------
                NAME    ?BANK?SWITCHING

?BANK?SELECT    SEGMENT  CODE
                RSEG    ?BANK?SELECT
?B_BANK0:       CLR     A
                JMP     @A+DPTR

?B_MODE         EQU     0

                PUBLIC  ?B_NBANKS, ?B_MODE, ?B_BANK0

                END

MORE INFORMATION

• Refer to Code Banking in the BL51 User's Guide.
• Refer to Configuration in the BL51 User's Guide.

SEE ALSO

• C51: Creating Code Banking Programs
• BL51: Using Function Pointers With Code Banking
• C51: Indirect Function Calls with Code Banking
• C51: Calculating Code Space for Bank Switching
• µVision1: Specifying Code Banks for Bank Switching
• BL51: The Code Banking Mechanism

Last Reviewed: Thursday, February 25, 2021