ARM Technical Support Knowledge Articles

ARE RAM BIT-ADDRESSABLE REGISTERS SUPPORTED?

Applies to: C51 C Compiler

Answer


Information in this article applies to:


QUESTION

Are RAM bit-addressable registers supported in C51?

ANSWER

The 8051’s SFR area from 0x80-0xFF and the bit-addressable range from 0x20-0x2F are both supported. Bit-addressable SFRs may be accessed both in C and assembly.

The C type sbit is designed specifically to assign a name to bits within SFRs.

The C type bit is designed to declare a bit variable in the bit-addressable area from 0x20 to 0x2F.

Article last edited on: 2004-05-17 16:53:37

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