M16C6KA_15 Datasheet, PDF (105/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Clock asynchronous serial I/O (UART) mode
Table.GA-7 lists the functions of the input/output pins during UART mode. Note that for a period from when
the UART1 operation mode is selected to when transfer starts, the TxD1 pin outputs a “H”. (If the N-channel
open-drain is selected, this pin is in floating state.)
Table.GA-7 Input/output pin functions in UART mode
Pin name
TXD1
RXD1
CLK1
Function
Serial data output
Serial data input
Programmable I/O port
Transfer clock input
Method of selection
Corresponding port direction register bit = "0".
(Can be used as an input port when performing transmission only)
Internal/external clock selection bit (bit 3 at address 03A816) = “0”
Internal/external clock selection bit (bit 3 at address 03A816) = “1”
Corresponding port direction register bit = “0”
CTS1/RTS1
CTS input
CTS/RTS disable bit (bit 4 at address 03AC16) =“0”
CTS/RTS function selection bit (bit 2 at address 03AC16) = “0”
Corresponding port direction register bit = “0”
RTS output
CTS/RTS disable bit (bit 4 at address 03AC16) = “0”
CTS/RTS function selection bit (bit 2 at address 03AC16) = “1”
Programmable I/O port CTS/RTS disable bit (bit 4 at address 03AC16) = “1”
Rev.1.00 Jul 16, 2004 page 103 of 266
REJ03B0100-0100Z