C51: xdata Banking with R8051XC

Information in this knowledgebase article applies to:

• C51 Version 8.16, or higher
• Evatronix R8051XC CPU core

QUESTION

I want to use the extended XDATA memory of the Evatronix R8051XC core.

How do I need to configure the tools? What is the physical and logical memory view of the 8051 system in this case?

ANSWER

The example in the folder C:\Keil\C51\Examples\R8051XC demonstrates the configuration of the extended xdata memory on an Evatronix R8051XC core.

The logical and physical memory mapping is shown below:

LOGICAL VIEW (TOOLS)                    PHYSICAL VIEW (HARDWARE)
----------------------------------------------------------------
X:0        - X:0x007FFF (common area)   0        - 0x007FFF
X:0x008000 - X:0x00FFFF (bank 0)        0        - 0x007FFF (must not be used!)
X:0x018000 - X:0x01FFFF (bank 1)        0x008000 - 0x00FFFF
X:0x028000 - X:0x02FFFF (bank 2)        0x010000 - 0x017FFF
    :          :                          :         :
X:0x078000 - X:0x07FFFF (bank 7)        0x038000 - 0x03FFFF

MORE INFORMATION

• Application Note 191: Toolchain Extensions for R8051XC Core

SEE ALSO

• C51: Configuring XDATA Banking

Last Reviewed: Thursday, February 25, 2021