DESCRIPTION
7905 Group User’s Manual Rev.1.0
1-5
Apply 5 V ± 0.5 V to pin Vcc and 0 V to pin Vss.
This pin switches the operating mode. This is only for the
single-chip mode, so connect this pin to VSS.
The microcomputer is reset when “L” level is input to this pin.
Pins XIN and XOUT are the input and output pins of the clock
generating circuit, respectively. Connect these pins via a
ceramic resonator or a quartz-crystal oscillator. When an
external clock is input, this clock should be input to pin XIN,
and pin XOUT should be left open.
To use the PLL frequency multiplier, be sure to connect this
pin to the filter circuit.
The power source input pin for the A-D converter. Connect this
pin to Vcc.
The power source input pin for the A-D and D-A converters.
Connect this pin to Vss.
This is the reference voltage input pin for the A-D and D-A converters.
P0 is an 8-bit CMOS I/O port and has an I/O direction register.
Each pin can function as an input or output port pin. By
software, these pins can function as I/O pins for serial I/O.
P2 is an 8-bit I/O port with the same function as port P1.
By software, these pins can function as I/O pins for timers
A4 and A9. Also, these pins can function as input pins for
timers B0 to B2.
P4 is an 8-bit I/O port with the same function as port P1.
By software, these pins can function as I/O pins for timers A5 to
A8, or as motor drive waveform output pins.
P5 is a 6-bit I/O port with the same function as port P1.
By software, these pins can function as input pins for timers B0
to B2, input pins for external interrupts, position data input pins
in the three-phrase waveform mode, or trigger input pins in the
pulse output port mode.
P6 is an 8-bit I/O port with the same function as port P1.
By software, these pins can function as I/O pins for timers A0 to
A3, or as motor drive waveform output pins.
1.3 Pin description
—
Input
Output
—
Input
I/O
Power source input
MD0
MD1
Reset input
Clock input
Clock output
Filter circuit connection
Analog power source
input
Reference voltage input
I/O port P1
I/O port P2
I/O port P4
I/O port P5
I/O port P6
Input/Output
Vcc, Vss
MD0
MD1
RESET
XIN
XOUT
VCONT
AVcc
AVss
VREF
P10–P17
P20–P27
P40–P47
P51–P53,
P55–P57
P60–P67
1.3 Pin description
Tables 1.3.1 and 1.3.2 list the pin description.
Table 1.3.1 Pin description (1)
Name
Pin
Function