M16C80 Datasheet, PDF (158/358 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/80 SERIES

M16C/80 Group
18. Clock asynchronous serial I/O (UART) mode
Table 18.3 lists the functions of the input/output pins during UART mode. This table shows the pin
_______ _______
functions when the separate CTS/RTS pins function is 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 18.3 Input/output pin functions in UART mode
Pin name
Function
TxDi
Serial data output
(P63, P67, P70, _{(Note 1)}
P92, P96)
RxDi
Serial data input
(P62, P66, P71, (Note 2)
P91, P97)
Method of selection
Port P62, P66, P71, P91 and P97 direction register (bits 2 and 6 at address
03C216, bit 1 at address 03C316, bit 1 and 7 at address 03C716)= “0”
(Can be used as an input port when performing transmission only)
CLKi
(P61, P65, P72,
P90, P95)
Programmable I/O port
(Note 2)
Transfer clock input
(Note 2)
Internal/external clock select bit (bit 3 at addresses 036016, 036816,
033816, 032816, 02F816) = “0”
Internal/external clock select bit (bit 3 at addresses 036016, 036816,
033816, 032816, 02F816) = “1”
Port P61, P65, P72, P90 and P95 direction register (bits 1 and 5 at address
03C216, bit 2 at address 03C316, bits 0 and 5 at address 03C716) = “0”
CTSi/RTSi
CTS input
(P60, P64, P73, (Note 2)
P93, P94)
RTS output (Note 1)
CTS/RTS disable bit (bit 4 at addresses 036416, 036C16, 033C16,
032C16, 02FC16) =“0”
CTS/RTS function select bit (bit 2 at addresses 036416, 036C16, 033C16,
032C16, 02FC16) = “0”
Port P60, P64, P73, P93 and P94 direction register (bits 0 and 4 at address
03C216, bit 3 at address 03C316, bits 3 and 4 at address 03C716) = “0”
CTS/RTS disable bit (bit 4 at addresses 036416, 036C16, 033C16, 032C16,
02FC16) = “0”
CTS/RTS function select bit (bit 2 at addresses 036416, 036C16, 033C16,
032C16, 02FC16) = “1”
Programmable I/O port _{CTS/RTS disable bit (bit 4 at addresses 036416, 036C16, 033C16, 032C16,}
(Note 2)
02FC16) = “1”
________ _______
(When separate CTS/RTS pins function is not selected)
________
Note 1: Select TxD output, CLK output and RTS output by the corresponding function select registers A, B
and C.
Note 2: Select I/O port by the corresponding function select register A.
Rev.1.00 Aug. 02, 2005 ^{Page 147} of 329
REJ09B0187-0100