mitsubishi - Al Kossow's Bitsavers

MITSUBISHI MICROCOMPUTERSMSM80S0H-XXXP/MSM8040HPSINGLE-CHIP a-BIT MICROCOMPUTERPIN DESCRIPTION'V ssVeeVooPin Name Input or outputGroundMain power supplyPower supplyTo Test pin 0InputOutputXl, X 2 Crystal inputs InputRESET Reset Input- SS Single step InputĪNT I f!terrupt InputEA External access Input- RO Read control OutputPSEN Program store enable Output- WR Write control OutputALE Address latch enable Output0 0-07 Data bus Input/outputP20-P27 Port 2Input/outputOutputInput/outputPROG Program OutputPl o -P1 7 Port 1 Input/outputTl Test pin 1 InputNormally connected to ground (OV).Connected t05V power supply.(DConnected t05V power supply.®Used for memory hold when Vcc is cut.Function(DControl signal from an external source for conditional jumping in a program. Jumping is dependent onexternal conditions (JTOfJNTO).®Used for outputting the internal clock signal (ENTO ClK).External crystal .oscillator or RC circuit input for generating internal clock signals.An external clock signal can be input through Xl or X2•Control used to initialize the CPU.Control signal used in conjunction with ALE to stop the CPU through each instruction, in the single-stepmode.(DControl signal from an external source for conditional jumping in a program. Jumping is dependent onexternal conditions (JNI).®Used for external interrupt to CPU.(DNormally maintained atOV.®When the level is raised t05V, external memory will be accessed. The M5M8040HP is raised t05V.Read control signal used when the CPU requests data from external data memory or external device tobe transferred to the data bus.(MOVX A, @R r , and INS A, BUS)Strobe signal to fetch external program memory.Write control signal used when the CPU sends data through the data bus to external data memory or externaldevice.(MOVX @Rr, A and OUTl BUS, A)A signal used for latching the address on the data bus. An ALE signal occurs once during each cycle.(DProvides true bidirectional bus transfer of instructions and data between the CPU and exterQal mem---ory. Synchronizing is done with signals RO/WR. The output data is latched.®When using external program memory, the output of the low-order 8 bits of the program counter aresynchronized with ALE. After that, the transfer of the instruction code or data from the external program--memory is synchronized with PSEN.@The output of addresses for data using the external data memory is synchronized with ALE. After that,--the transfer of data with the external data memory is synchronized with RO/WR.(MOVX A, @R r , and MOVX @R r , A)(DQuasi-bidirectional port. When used as an input port, FF 16 must first be output to this port. After reset,when not used as an output port, nothing needs to be output.®P2o-P2 3 output high-order 4 bits of the program counter when using external program memory.@P2 0 -P2 3 serve as a 4-bit I/O expander bus for the M5l8243P.Strobe signal for M5l8243P I/O expander.Quasi-bidirectional port. When used as an input port, FF 16 must first be output to this port. After reset,when not used as an output port, nothing needs to be output.(DControl signal from an external source for conditional jumping in a program. Jumping is dependent onexternal conditions (JT1/JNT1).®When enabled, event signals are transferred to the timer/event counter (STRT CNT).II.• MITSUBISHI.... ELECTRIC4-35