The following functions are allocated to the pins in boot mode.
・PA4/A4/IRQ2/TXD1 pin: TXD1
・PA3/A3/IRQ1/RXD1 pin: RXD1
・Other pins : initial function in "MCU extension mode2".
For the allocated pin function set in On-Chip ROM Enabled mode, please see "Table 17.11 SH7149 Pin Functions in Each Operating Mode (2)" in "SH7146 Group User's Manual: Hardware".