[Sdcc-user] Banking 101 for 18F PICs

[Bob S. <bo...@ev...>]

I've been developing someone else's assembly code in Piklab for 18F2220 for about a year and I'd like to move at least some of it to C as a learning experience for another project I want to do.  I have variables in the Access Bank, Bank0, and Bank1.  I only access the variables in Bank0 via FSR, so I don't have to mess with banking for the rest. I cannot figure out how to duplicate this in C on SDCC.  I'm not new to C, just to C with micros.  I'm certainly new to banking in a C environment.

As an example, the following (which are defined in CBLOCKs in the assembly code).  How do I define them in sdcc, and access them as described above?  Do I use small or large memory model?  I can't even figure out how to begin.

Access ram:
    TEMP1_H                  ;13_Temporary 16-bit var available throughout code execution.
    TEMP1_L                  ;14_ "

Bank0:
    TIC_CAL_0                ;00_Address of first value beginning with 0x00
    TIC_CAL_1                ;01_Address of first value beginning with 0x01
    TIC_CAL_TABLE:.99 

Bank1:
    OLD_CCPR1L               ;0_Previous CCPR1L value
    OLD_CCPR1H               ;1_Previous CCPR1H value


Bob - AE6RV