M16C6K9 Datasheet, PDF (109/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
Serial I/O
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 and the separation of CTS/RTS pins
are not selected. Note that for a period from when the UARTi operation mode is selected to when transfer
starts, the TxDi 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. The function that separates
CTS/RTS pins is not selected.)
Pin name
Function
Method of selection
TxDi
Serial data output
(Outputs dummy data when performing reception only)
RxDi
Serial data input
The corresponding bit of port direction register = “0”
(Can be used as an input port when performing transmission only)
CLKi
Transfer clock output
Transfer clock input
Internal/external clock select bit (bit 3 at address 03A016, 03A816, 037816) = “0”
Internal/external clock select bit (bit 3 at address 03A016, 03A816, 037816) = “1”
The corresponding bit of port direction register = “0”
CTSi/RTSi
CTS input
RTS output
Programmable I/O port
CTS/RTS disable bit (bit 4 at address 03A416, 03AC16, 037C16) =“0”
CTS/RTS function selection bit (bit 2 at address 03A416, 03AC16, 037C16) = “0”
The corresponding port direction bit = “0”
CTS/RTS disable bit (bit 4 at address 03A416, 03AC16, 037C16) = “0”
CTS/RTS function selection bit (bit 2 at address 03A416, 03AC16, 037C16) = “1”
CTS/RTS disable bit (bit 4 at address 03A416, 03AC16, 037C16) = “1”
Rev.1.00 Jun 06, 2003 page 109 of 290