M30622SAFP MITSUBISHI [Mitsubishi Electric Semiconductor], M30622SAFP Datasheet - Page 257

• Manufacturer Part Number: M30622SAFP
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

Appendix Standard Serial I/O Mode 2 (Flash Memory Version)
Overview of standard serial I/O mode 2 (clock asynchronized)
Figure 1.29.22. Peripheral unit and initial communication
In standard serial I/O mode 2, software commands, addresses and data are input and output between the
MCU and peripheral units (serial programer, etc.) using 2-wire clock-asynchronized serial I/O (UART1).
Standard serial I/O mode 2 is engaged by releasing the reset with the P6
The TxD
After the reset is released, connections can be established at 9,600 bps when initial communications (Fig-
ure 1.29.22) are made with a peripheral unit. However, this requires a main clock with a minimum 2 MHz
input oscillation frequency. Baud rate can also be changed from 9,600 bps to 19,200, 38,400 or 57,600 bps
by executing software commands. However, communication errors may occur because of the oscillation
frequency of the main clock. If errors occur, change the main clock's oscillation frequency and the baud
rate.
After executing commands from a peripheral unit that requires time to erase and write data, as with erase
and program commands, allow a sufficient time interval or execute the read status command and check
how processing ended, before executing the next command.
Data and status registers in memory can be read after transmitting 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. Here following are explained initial communications with
peripheral units, how frequency is identified and software commands.
Initial communications with peripheral units
After the reset is released, the bit rate generator is adjusted to 9,600 bps to match the oscillation fre-
quency of the main clock, by sending the code as prescribed by the protocol for initial communications
with peripheral units (Figure 1.29.22).
*1. If the peripheral unit cannot receive "B0
(1) Transmit "B0
(2) Transmit "00
(3) The MCU with internal flash memory outputs the "B0
MHz, the MCU with internal flash memory outputs the "B0
is anything other than 10 or 16 MHz, the MCU does not output anything.
rate generator so that "00
successfully *
interval of a minimum 15 ms. Also, the baud rate at the end of initial communications is 9,600 bps.
1
pin is for CMOS output. Data transfer is in 8-bit units with LSB first, 1 stop bit and parity OFF.
(1) Transfer "B0
(2) Transfer "00
At least 15ms
transfer interval
16
16
1
. Initial communications must be transmitted at a speed of 9,600 bps and a transfer
" from a peripheral unit. If the oscillation frequency input by the main clock is 10 or 16
" from a peripheral unit 16 times. (The MCU with internal flash memory sets the bit
16
16
" 16 times
Peripheral unit
"
The bit rate generator setting completes (9600bps)
15 th
16th
16
1st
2nd
" can be successfully received.)
16
" successfully, change the oscillation frequency of the main clock.
"B0
"B0
"B0
"00
"00
"00
"00
16
16
16
16
16
16
16
"
"
"
"
"
"
"
16
" check code and initial communications end
MCU with internal
16
flash memory
" check code. If the oscillation frequency
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(3) Transfer check code "B0
If the oscillation frequency input
by the main clock is 10 or 16
MHz, the MCU outputs "B0
other than 10 or 16 MHz, the
MCU does not output anything.
5
Reset
(CLK
1
) pin "L" level.
M16C / 62A Group
Mitsubishi microcomputers
16
16
"
". If
257