hello, i am using 89c51rd2BN from philips,i want to store 100 bytes of data as buffers,presently i am storing it in the RAM,however if the 128 byte RAM exceeds,what do i do,in datasheet of 89c51rd2 it says that 89c51rd2 has 256 Bytes on-chip RAM,and 768 Bytes on-chip XRAM,please let me know how do i use or access this memory. regards, nafis
I am using 89c51rd2BN from philips,i want to store 100 bytes of data as buffers,presently i am storing it in the RAM,however if the 128 byte RAM exceeds,what do i do,in datasheet of 89c51rd2 it says that 89c51rd2 has 256 Bytes on-chip RAM,and 768 Bytes on-chip XRAM,please let me know how do i use or access this memory. Time for manual study read up on DATA IDATA and XDATA I suggest you read a whole lot more, since this question indicates that you have read basically nothing. Erik
256 bytes RAM. It's like buying something and reading an advertisement. Do you get to use the whole 256 or does the micro need some for it's operations? As stated, read the manual carefully.
Do you get to use the whole 256 or does the micro need some for it's operations? As stated, read the manual carefully. This does not make sense, OF COURSE, he "get to use the whole 256" no '51 derivative (I know of - correct me if I'm wrong) is different there. Erik
I was thinking of the stack.
or does the micro need some for it's operations .... I was thinking of the stack. Again, the use of the stack, just as storing variables is BOTH "something "the micro need some for it's operations" if you want to use that language. Storing variables and saving returns are both results of something you tell the uC to so, not some memory grab for "other purposes". Erik
Trying to determine the amount of memory required for stack operations isn't as clearly visible as reading the memory declarations in a set of modules and adding up bytes. Simply setting a stacksize parameter is no big deal but estimating the usage is not nearly as straight forward as checking the memory map. Sometimes the stack gets overlooked when people think about their memory needs, that was my original point.