MM36SB020 two-wire wiring circuit diagram

After the chip is powered on, when the strobe signal IEB remains low, instructions , addresses, and data can be written or read to the memory. All instructions
, addresses, and data are transmitted starting from the low-order bit (LSB). There are two special instructions
; RMEC and WEBC. RMEC continuously reads data from the memory. It must
enter the RMEC instruction after the instruction RME is executed. If the address is not entered,
the address of RME will be automatically incremented; the same is true for the WEBC instruction, which must be executed after the WEB instruction
is executed.
    When MM36SB020 is connected to the microcontroller of the controller, it adopts 2-wire serial
bus mode, and the software uses query/control mode. The hardware connection coil
is shown in Figure 27-55.
    4) Keyboard module: During the normal operation of the Menrong system, community users
need to key in the card and password to open the door without carrying the card. The system is
required to set up a keyboard interface with multiple buttons during system design. , Ordinary array keyboards
occupy a large amount of I/O resources. In order to reduce the number of I/O ports, the HD7279A keyboard display smart chip was selected in the design.