M16C28 Datasheet, PDF (388/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
20. Precautions
20.8.2 UART Mode
20.8.2.1 Special Mode 1 (I²C bus Mode)
When generating start, stop and restart conditions, set the STSPSEL bit in the U2SMR4 register to “0”
and wait for more than half cycle of the transfer clock before setting each condition generate bit
(STAREQ, RSTAREQ and STPREQ) from “0” to “1”.
20.8.2.2 Special Mode 2
_____
If a low-level signal is applied to the SD pin when the IVPCR1 bit in the TB2SC register is set to "1"
_____
________
(three-phase output forcible cutoff by input on SD pin enabled), the RTS2 and CLK2 pins go to a high-
impedance state.
20.8.2.3 Special Mode 4 (SIM Mode)
A transmit interrupt request is generated by setting the U2C1 register U2IRS bit to “1” (transmission
complete) and U2ERE bit to “1” (error signal output) after reset. Therefore, when using SIM mode, be
sure to clear the IR bit to “0” (no interrupt request) after setting these bits.
20.8.3 SI/O3, SI/O4
The SOUTi default value which is set to the SOUTi pin by the SMi7 bit approximately 10ns may be output
when changing the SMi3 bit from "0" (I/O port) to "1" (SOUTi output and CLK function) while the SMi2 bit
in the SiC (i=3 and 4) to "0" (SOUTi output) and the SMi6 bit is set to "1" (internal clock). And then the
SOUTi pin is held high-impedance.
If the level which is output from the SOUTi pin is a problem when changing the SMi3 bit from "0" to "1", set
the default value of the SOUTi pin by the SMi7 bit.
Rev. 2.00 Jan. 31, 2007 ^{page 368} of 385
REJ09B0047-0200