sc1200?

Devi Priya ijpriya at hotmail.com
Wed Dec 17 21:45:01 CET 2003


Hi,
After power-on, the x86 processor is placed in real mode. That means the CPU 
looks for the instruction at the address 0xffff0. Is it correct? In SC1200 
datasheet, it is given that,
"Approximately 150 to 250 external clock cycles after RESET is deasserted, 
the processor begins executing instructions at the top of physical memory 
(address location
FFFFFFF0h). The actual number of clock cycles depends on the clock scaling 
in use. Also, before execution begins, an additional 220 clock cycles are 
needed when self-test is
requested. Typically, an intersegment jump is placed at FFFFFFF0h. This 
instruction will force the processor to begin execution in the lowest 1 MB 
of address space."
In real mode, the CPU can address only 1 MB. Then how this address could be 
addressed by the CPU?
To which address does my Flash memory gets mapped to at power-on?

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