Let’s discuss the ARM registers within the core. The ARM7 core has thirty-seven registers that are each 32 bits wide. Of the thirty-seven registers, eighteen are general purpose, one is a Program Counter (PC) register, six are Link Registers (LRs), six are Stack Pointer (SP) registers, one is a Current Program Status Register (CPSR), and five are Saved Program Status Registers (SPSRs). These registers are not all accessible at the same time since they belong to different register banks.