M16C6KA_15 Datasheet, PDF (98/270 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER Description

M16C/6KA Group
Clock synchronous serial I/O mode
Table.GA-4 lists the functions of the input/output pins during clock synchronous serial I/O mode. This table
shows the pin functions that the transfer clock output from multiple pins are not selected. 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-4 Input/output pin functions in clock synchronous serial I/O mode
(The function that the transfer clock output from multiple pin is not selected.)
Pin name
TxD1
RxD1
Function
Serial data output
Serial data input
Method of selection
(Outputs dummy data when performing reception only)
The corresponding bit of port direction register = “0”
(Can be used as an input port when performing transmission only)
CLK1
Transfer clock output
Internal/external clock select bit (bit 3 at address 03A816) = “0”
Transfer clock input
Internal/external clock select bit (bit 3 at address 03A816) = “1”
The corresponding bit of port direction register = “0”
CTS1/RTS1
CTS input
RTS output
Programmable I/O port
CTS/RTS disable bit (bit 4 at address 03AC16) =“0”
CTS/RTS function selection bit (bit 2 at address 03AC16) = “0”
The corresponding port direction bit = “0”
CTS/RTS disable bit (bit 4 at address 03AC16) = “0”
CTS/RTS function selection bit (bit 2 at address 03AC16) = “1”
CTS/RTS disable bit (bit 4 at address 03AC16) = “1”
Rev.1.00 Jul 16, 2004 page 96 of 266
REJ03B0100-0100Z