M30222 Datasheet, PDF (206/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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Specifications in this manual are tentative and subject to change
MITSUBISHI MICROCOMPUTERS
M30222 Group
Rev. G
Serial I/O Mode 1 (Flash Memory Version)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Overview of standard serial I/O mode 1 (clock synchronous)
In standard serial I/O mode 1, software commands, addresses and data are input and output between
the MCU and peripheral units (serial programmer, etc.) using 4-wire clock-synchronous serial I/O
(UART1). Standard serial I/O mode 1 is engaged by releasing the reset with the P56 (CLK1) pin “H”
level.
In reception, software commands, addresses and program data are synchronized with the rise of the
transfer clock that is input to the CLK1 pin, and are then input to the MCU via the RxD1 pin. In transmis-
sion, the read data and status are synchronized with the fall of the transfer clock, and output from the
TxD1 pin.
The TxD1 pin is for CMOS output. Transfer is in 8-bit units LSB first.
When busy, such as during transmission, reception, erasing or program execution the RTS1 (BUSY)
pin is “H” level. Accordingly, always start the next transfer after the RTS1 (BUSY) pin is “L” level.
Also, data and status register in memory can be read after inputting software commands. Status, such
as the operating state of the flash memory or whether a program or erase operation ended successfully
or not, can be checked by reading the status register.
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