Forum : 8051
Original Post
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November 6, 2008 - 5:30am
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Hai, The RAM address of 8051 Port 0 is 80h, If i want to use as bit addressing, we need to use as 80h,81h,82h....,87h. But the SP RAM address is 81h, and understand, how can i use this. I am using RIDE for uC programming. for bit addressing i need to specify the RAM location, If i assign like P0_1=81h, then is it refelect in SP or not? I could not understand this logic. Please help me. Thanks and Regards, |
RAM is directly addressable only between 00H and 80H. If you want to address the internal ram between 80H and 0FFH, you must use an indirect addressing mode. (using either R0 or R1 as pointer).
Only the range [20H,2FH] is bit addressable.