The PIC16F1503-I/SL is a 14-pin/8-bit Flash Microcontroller. This family of devices contain an enhanced mid-range 8-bit CPU core. The CPU has 49 instructions. Interrupt capability includes automatic context saving. The hardware stack is 16 levels deep and has Overflow and underflow reset capability. Direct, indirect and relative addressing modes are available. Two file select registers (FSRs) provide the ability to read program and data memory. During interrupts, certain registers are automatically saved in shadow registers and restored when returning from the interrupt. The flash program memory is readable and writable during normal operation over the full VDD range. Program memory is indirectly addressed using special function registers (SFRs).