NEC uPD78056Y - Manual (Page 85)

85
CHAPTER 4 PIN FUNCTION (
µ
PD78054Y Subseries)
4.2.10 P130 and P131 (Port 13)
These are 2-bit input/output ports. Besides serving as input/output ports, they are used for D/A converter analog
output.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These ports function as 2-bit input/output ports. They can be specified in 1-bit units as input or output ports
with port mode register 13 (PM13). When they are used as input ports, on-chip pull-up resistors can be used
by defining the pull-up resistor option register H (PUOH).
(2) Control mode
These ports allow D/A converter analog output (ANO0 and ANO1).
Caution When only either one of the D/A converter channels is used with AV REF1 < V DD , the other pins
that are not used as analog outputs must be set as follows:
• Set PM13x bit of the port mode register 13 (PM13) to 1 (input mode) and connect the pin
to V SS .
• Set PM13x bit of the port mode register 13 (PM13) to 0 (output mode) and the output latch
to 0, to output low level from the pin.
4.2.11 AV REF0
A/D converter reference voltage input pin.
When A/D converter is not used, connect this pin to V SS .
4.2.12 AV REF1
D/A converter reference voltage input pin.
When D/A converter is not used, connect this pin to V DD .
4.2.13 AV
DD
Analog power supply pin of A/D converter. Always use the same voltage as that of the V
DD
pin even when A/D
converter is not used.
4.2.14 AV SS
This is a ground voltage pin of A/D converter and D/A converter. Always use the same voltage as that of the V SS
pin even when neither A/D nor D/A converter is used.
4.2.15 RESET
This is a low-level active system reset input pin.