ffixed option for R12

I would like to reserve R12 for my application in Thumb mode, but I don't know how to make it with Keil uVisionV5. GCC has -ffixed-reg (don't know if or how it works). I am compiling now for Arm Cortex...
ffixed option for R12

I would like to reserve R12 for my application in Thumb mode, but I don't know how to make it with Keil uVisionV5. GCC has -ffixed-reg (don't know if or how it works). I am compiling now for Arm Cortex...
Want to know the difference

I want to know the differences between the following two definiations: (*((volatile char xdata *)( CHIP_BASE + i))) ((volatile char xdata *)( CHIP_BASE + PTR_BASE + PTR_SIZE * i)) Thank you....
Want to know the difference

I want to know the differences between the following two definiations: (*((volatile char xdata *)( CHIP_BASE + i))) ((volatile char xdata *)( CHIP_BASE + PTR_BASE + PTR_SIZE * i)) Thank you....
wanted to know about ARM7 programming

Dear to all , i have to work with ARM7 platform. give me guidance to get proper study material for programming in ARM7 starting from the scratch