R8C/1A Group, R8C/1B Group
5. Programmable I/O Ports
Rev.1.30
Dec 08, 2006
Page 36 of 315
REJ09B0252-0130
X: 0 or 1
X: 0 or 1
X: 0 or 1
Table 5.15
Port P3_7/CNTR0/SSO/TXD1
Register
PD3
PUR0
U1MR
SSU (Refer to
Table 16.4
Association between
Communication Modes
and I/O Pins
)
TXMR
UCON
Function
Bit
PD3_7
PU07
SMD2,
SMD1, SMD0
SSO Output
Control
SSO Input
Control
TXOCNT
U1SEL1,
U1SEL0
Setting
Value
0
0
000b
0
0
0
0Xb
Input port (not pulled up)
0
1
000b
0
0
0
0Xb
Input port (pulled up)
1
X
000b
0
0
0
0Xb
Output port
X
X
001b
0
0
X
11b
TXD1 output pin
100b
101b
110b
X
X
000b
0
0
1
XXb
CNTR0 output pin
X
X
XXXb
0
1
X
XXb
SSO input pin
X
X
XXXb
1
0
X
XXb
SSO output pin
Table 5.16
Port XIN/P4_6, XOUT/P4_7
Register
CM1
CM1
CM0
Circuit Specification
Function
Bit
CM13
CM10
CM05
Oscillation
Buffer
Feedback
Resistance
Setting
Value
1
1
1
OFF
OFF
XIN-XOUT oscillation stop
1
0
1
OFF
ON
External input to XIN pin, “H” output
from XOUT pin
1
0
1
OFF
ON
XIN-XOUT oscillation stop
1
0
0
ON
ON
XIN-XOUT oscillation
0
X
X
OFF
OFF
Input port
Table 5.17
Port P4_5/INT0/RXD1
Register
PD4
PUR1
UCON
INTEN
Function
Bit
PD4_5
PU11
U1SEL1, U1SEL0
INT0EN
Setting
Value
0
0
00b
0
Input port (not pulled up)
0
1
00b
0
Input port (pulled up)
0
0
00b
1
INT0 input (not pulled up)
0
1
00b
1
INT0 input (pulled up)
X
0
01b
0
RXD1 input
11b
1
X
00b
X
Output port