mg84fl54b Megawin Technology, mg84fl54b Datasheet - Page 15

• Manufacturer Part Number: mg84fl54b
• Description: Full-speed Usb Micro-controller
• Manufacturer: Megawin Technology

7. On-chip expanded RAM (XRAM)
In addition to the 256 bytes of scratch-pad RAM, there are extra 576 bytes of on-chip expanded RAM (XRAM) in
USB MCU Mode. They may be accessed by the instructions “MOVX @Ri” and “MOVX @DPTR”.
Using the XRAM in Software
For KEIL-C51 compiler, to assign the variables to be located at XRAM, the “pdata” or “xdata” definition should
be used. After being compiled, the variables declared by “pdata” and “xdata” will become the memories
accessed by “MOVX @Ri” and “MOVX @DPTR”, respectively. Thus the BA126 hardware can access them
correctly. The user can get the following descriptions from the “Keil Software — Cx51 Compiler User’s Guide”.
MEGAWIN
MG84FL54B Data sheet
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