HD6805S1

      The HD6805S1 is the 8-bit microcomputer unit (MCU) which contains a CPU,on-chip clock,ROM,RAM,I/O and timer.HD6805S1 is designed for use who needs an economical microcomputer with the proven capabilities of the HD 6800-based instruction set.
      The following are some of the hardware and software highlights of the HD6805S1 MCU.First is about the hardware feature.It has 8-bit architecture,64 bytes of RAM,memory mapped I/O,1100 bytes of user ROM and internal 8-bit timer with 7-bit prescaller.Besides,it contains vectored interrupts-external and timer.There are 20 TTL/CMOS compatible I/O lines and 8 lines LED compatible.On-choi clock circuit,self-check mode,master reset,low voltage inhibit are notable features.What's more,it is easy for system development and debugging and compatible with MC6805P2.Then is about the software features.It is similar to HD6800 and easy to program.Byte efficient instruction set,true bit manipulation,bit test and branch instruction,verstaile interrupt function are distinct characteristics.It is powerful indexed addressing for tables and has full set of conditional branches.It has single instruction memory examine/change and 10 powerful addressing modes.Besides,all addressing modes apply to ROM,RAM and I/O.It is compatible with MC6805P2.
      What comes next is about the absolute maximum ratings of HD6805S1.The supply voltage (V_CC) is from -0.3 to 7.0V.The input voltage (except timer) (V_IN) is from -0.3 to +7.0V and the input voltage (timer) (V_IN) is from -0.3 to +12.0V.The operating temperature (T_opr) is from 0 to +70.The storage temperature (T_stg) is from -55 to +70.The maximum power dissipation (P_D) is 700mW.The maximum low voltage recover (LVR) is 4.75V and the typical low voltage inhibit (LVI) is 4.0 V.