EM78P153B is an 8-bit microcontroller designed and developed with low power consumption and high speed CMOS technology. It has a 1024x13-bit one-time programmable read-only memory (OTP-ROM) inside. It provides three protection bits to prevent the user's program in the OTP-ROM from being stolen. There are 15 code option bits to meet the needs of user-customized code functions. Utilizing its OTP-ROM feature, EM78P153B allows users to easily develop and verify programs, and use the "ELAN programmer" to easily complete IC program programming.

EM78 internal structure block diagram

EM78X56 integrates an 8-bit arithmetic operation unit ALU and working register ACC, 1K～4KROM, 56 RAM, 12 I/O ports, and 8-bit prescaler on-chip

And 8-bit counter (TCC), oscillator, watchdog, five-level stack, interrupt controller, instruction register, decoder and other registers. The EM78 series single-chip microcomputer adopts an independent Harvard structure with 8-bit data/control bus and 13-bit instruction bus. Pipeline instructions, that is, when an instruction is being executed,

The next instruction has been fetched from the ROM and placed in the instruction register for execution, so almost all of the EM78 series are single-cycle instructions with faster execution speed. EM78 series data memory can be regarded as registers for addressing programming, divided into two categories: working registers and special function registers. Section 2.5 will describe the use of registers in detail.