SN8P2711A
8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 107
Version 0.1
9.5 P4CON
REGISTERS
The Port 4 is shared with ADC input function. Only one pin of port 4 can be configured as ADC input in the same time
by ADM register. The other pins of port 4 are digital I/O pins. Connect an analog signal to COMS digital input pin,
especially the analog signal level is about 1/2 VDD will cause extra current leakage. In the power down mode, the
above leakage current will be a big problem. Unfortunately, if users connect more than one analog input signal to port 4
will encounter above current leakage situation. P4CON is Port4 Configuration register. Write “1” into P4CON [7:0] will
configure related port 4 pin as pure analog input pin to avoid current leakage.
0AEH
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
P4CON
-
-
-
P4CON4 P4CON3 P4CON2 P4CON1 P4CON0
Read/Write
-
-
- R/W R/W R/W R/W R/W
After
reset
- - - 0 0 0 0 0
Bit[4:0]
P4CON[4:0]:
P4.n configuration control bits.
0 = P4.n can be an analog input (ADC input) or digital I/O pins.
1 = P4.n is pure analog input, can’t be a digital I/O pin.
Note: When Port 4.n is general I/O port not ADC channel, P4CON.n must set to “0” or the Port 4.n digital
I/O signal would be isolated.