Can I use of all general purpose registers for fast operations?

My previous project was built on STM32F051K4U7 microcontroller using the legacy Arm compiler (v5.06). For fast data operations I used general purpose registers r5 all the way up to r11 (7 in total). The...
Hexadecimal Arithmetic

I want to carry out following Hexadecimal Arithmetic operation using C code Multiplication...................................... char A[2] = { 0x01, 0x02}; char B[2] = { 0x03, 0x04}; I want...
Hexadecimal Arithmetic

I want to carry out following Hexadecimal Arithmetic operation using C code Multiplication...................................... char A[2] = { 0x01, 0x02}; char B[2] = { 0x03, 0x04}; I want...
Pointer conversion / arithmetic

Hello, I am trying to create an address (memory model huge) by adding an offset to a base address: void test (unsigned short offset) { unsigned char *adr; adr = 0x120000 + (long) adr; } ...
dr80390 arithmetic accelerator

Hi Sir, I install keil c7.10. and choose device dr80c390,and check arithmetic accelerator. compile pass. But the div and shift operate result is wrong. something like DWORD i,j,k; k = i / j; k ...