I_ST macro

Store value from register reg_val into RTC memory. The value is written to an offset calculated by adding value of reg_addr register and offset_ field (this offset is expressed in 32-bit words). 32 bits written to RTC memory are built as follows: - bits [31:21] hold the PC of current instruction, expressed in 32-bit words - bits [20:18] = 3'b0 - bits [17:16] reg_addr (0..3) - bits [15:0] are assigned the contents of reg_val RTC_SLOW_MEM[addr + offset_] = { insn_PC[10:0], 3'b0, reg_addr, reg_val[15:0] }