Bit Rate Automatic Adjustment Procedure - Renesas RX100 Series User Manual

RX13T Group
31.11.1

Bit Rate Automatic Adjustment Procedure

The MCU measures the low width of data 00h that is sent from the serial programmer at 9,600 or 19,200 bps to
automatically adjust the bit rate.
Transmission to
the MCU
Reception from
the MCU
Figure 31.27 Transmit/Receive Data for Bit Rate Automatic Adjustment
After starting up in boot mode, wait for at least 400 ms and then send 00h to the MCU from the serial programmer. When
the bit rate adjustment is completed, the MCU sends 00h to the programmer. When the programmer receives 00h, send
55h to the MCU from the programmer. When the programmer can not receive 00h, wait for at least 1 ms and send 00h to
the MCU again. When the programmer fails to receive 00h even if it send 00h 30 times, restart the MCU in boot mode
and perform the automatic adjustment for the bit rate again.
When the MCU receives 55h, the MCU sends E6h and enters the inquiry/setting command wait state. If the MCU fails to
receive 55h, the MCU sends FFh. When the programmer receives FFh, restart the MCU in boot mode, and perform the
automatic adjustment for the bit rate again.
Serial
programmer
Release the
Wait for 400 ms
See
Note 1
See
Note 2
Note 1. When a value other than 00h is received, restart in boot mode and send a bit rate automatic adjust
command again.
Note 2. When FFh is returned, restart in boot mode and send a bit rate automatic adjust command again.
Figure 31.28 Bit Rate Automatic Adjustment Procedure
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
At least 1 ms
between commands
00h 00h
(1) (2)
Note 1. Maximum 30 times
reset
00h (automatic adjustment completed)
55h (automatic adjustment confirmed)
E6h (55h received successfully) or FFh (error)
00h
(3) ...
00h (maximum 30 times)
31. Flash Memory (FLASH)
00h 55h
*1
00h
MCU
Measure 9-bit
length
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