What does the word UNPREDICTABLE exactly mean and what is its effect on the system?

Hi, In many of ARM documentation result of operations are reported as unpredictable in some situations. For example, "If the system includes the Security Extensions, accesses to CNTVOFF from Secure Monitor...
What does the word UNPREDICTABLE exactly mean and what is its effect on the system?

Hi, In many of ARM documentation result of operations are reported as unpredictable in some situations. For example, "If the system includes the Security Extensions, accesses to CNTVOFF from Secure Monitor...
How does compiler C51 realize the key word reentrant?

In the following example,the chip is Dallas390 and the off-chip xdata starts from x:0x20000.Large model and large reentrant function stack is selected. The C language source: unsigned char func1(unsigned...
How does compiler C51 realize the key word reentrant?

In the following example,the chip is Dallas390 and the off-chip xdata starts from x:0x20000.Large model and large reentrant function stack is selected. The C language source: unsigned char func1(unsigned...
Why does ARM core product is named "cortex",what's the cortex mean, or which words combination of it

Hello everyone: I know all the ARM cpu is named cortex,but I don't know what is the "cortex" mean all the time.Maybe it is combination by some words,but what words they are.I search some material,but...