Clock asynchronous serial I/O (UART) mode
deveopmen
Preliminary Specifications REV.D
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C/80 (100-pin version) group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
143
Table 1.18.3 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 1.18.3. Input/output pin functions in UART mode
Pin name
TxDi
(P6
3
, P6
7
, P7
0
,
P9
2
, P9
6
)
Function
Method of selection
Serial data output
(Note 1)
Serial data input
(Note 2)
Programmable I/O port
(Note 2)
Transfer clock input
(Note 2)
Programmable I/O port
(Note 2)
Internal/external clock select bit (bit 3 at addresses 0360
16
, 0368
16
,
0338
16
, 0328
16
, 02F8
16
) = “0”
Internal/external clock select bit (bit 3 at addresses 0360
16
, 0368
16
,
0338
16
, 0328
16
, 02F8
16
) = “1”
Port P6
1
, P6
5
, P7
2
, P9
0
and P9
5
direction register (bits 1 and 5 at address
03C2
16
, bit 2 at address 03C3
16
, bits 0 and 5 at address 03C7
16
) = “0”
Port P6
2
, P6
6
, P7
1
, P9
1
and P9
7
direction register (bits 2 and 6 at address
03C2
16
, bit 1 at address 03C3
16
, bit 1 and 7 at address 03C7
16
)= “0”
(Can be used as an input port when performing transmission only)
CTS/RTS disable bit (bit 4 at addresses 0364
16
, 036C
16
, 033C
16
,
032C
16
, 02FC
16
) =“0”
CTS/RTS function select bit (bit 2 at addresses 0364
16
, 036C
16
, 033C
16
,
032C
16
, 02FC
16
) = “0”
Port P6
0
, P6
4
, P7
3
, P9
3
and P9
4
direction register (bits 0 and 4 at address
03C2
16
, bit 3 at address 03C3
16
, bits 3 and 4 at address 03C7
16
) = “0”
CTS input
(Note 2)
RTS output
RxDi
(P6
2
, P6
6
, P7
1
,
P9
1
, P9
7
)
CLKi
(P6
1
, P6
5
, P7
2
,
P9
0
, P9
5
)
CTSi/RTSi
(P6
0
, P6
4
, P7
3
,
P9
3
, P9
4
)
CTS/RTS disable bit (bit 4 at addresses 0364
16
, 036C
16
, 033C
16
, 032C
16
,
02FC
16)
= “0”
CTS/RTS function select bit (bit 2 at addresses 0364
16
, 036C
16
, 033C
16
,
032C
16
, 02FC
16
) = “1”
CTS/RTS disable bit (bit 4 at addresses 0364
16
, 036C
16
, 033C
16
, 032C
16
,
02FC
16
) = “1”
(Note 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.