It may be reserved for future use.In addition to the existing 21 SFRs , the new derivatives of 8051 microcontroller family provides new features with additional SFRs.These new SFRs occupy the certain locations from unused space of SFR(80H to FFH).Still there are unused locations left.
Hello! The relay type you are considering in your example come with a range of nominal coil pull-in voltages, from 3 Amp up to 48VDC. You chose to use the 12VDC version. Would it make more sense to go to a lower voltage range, the 3VDC or 5VDC version for convenience of using the available power supply used for the TTL logic? Or do you deliberately separate the relay control circuit from the MCU power supply circuit?
