There are absolute memory macros to access memory addresses in 8051, do we have any such to access externally connected flash through 8051?
I tried using C pointers, it does not seem to be reading the address in flash, How do we read & write from a memory location? Please help.
i mean, ya 8051 and flash chip to be interfaced, and flash chip is SPI compatible, have been asking about the same thing from the beginning, I didnt understand,
Ya, very same flash , and talking about address locations and those operations in flash,
"Wonder why, if 8 bit CMDs can be sent fine, Status register can be written to and read from, why reading from an address (or writing to) cannot be done using the same functions, they are sent as same 8 bits, what is the difference,"
That made absoultely no sense at all in the context of this thread!
Then I remembered your other thread: http://www.keil.com/forum/docs/thread8478.asp
You're talking about your SPI-interfaced flash chip now, aren't you?
Remember - the SPI interface means that your flash chip does not appear in any 8051 address space!
Thank you, going through them,
Wonder why, if 8 bit CMDs can be sent fine, Status register can be written to and read from, why reading from an address (or writing to) cannot be done using the same functions, they are sent as same 8 bits, what is the difference,
the so-called "bible" for the 8051:
Chapter 1 - 80C51 Family Architecture: www.nxp.com/.../80C51_FAM_ARCH_1.pdf
Chapter 2 - 80C51 Family Programmer's Guide and Instruction Set: www.nxp.com/.../80C51_FAM_PROG_GUIDE_1.pdf
Chapter 3 - 80C51 Family Hardware Description: www.nxp.com/.../80C51_FAM_HARDWARE_1.pdf
Here are some other introductory & reference materials: http://www.keil.com/books/8051books.asp www.8052.com/books.phtml www.8052.com/tutorial.phtml
Do you understand the 8051's distinct CODE and XDATA memory spaces?
You need to understand these things before you will be able to understand the facilities that C51 provides to access them!
http://www.keil.com/support/man/docs/c51/c51_le_memareas.htm
http://www.keil.com/support/man/docs/c51/c51_le_memtypes.htm
http://www.keil.com/support/man/docs/c51/c51_lib_macros.htm
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