
FLASH MEMORY VERSION
7905 Group User’s Manual Rev.1.0
19-20
19.3 Flash memory serial I/O mode
VCC
VSS
MD0
MD1
RESET
XIN
XOUT
VCONT
AVCC
AVSS
VREF
P10 to P17
P20 to P23,
P27
P24
P25
P26
P40 to P47
P51 to P53,
P55 to P57
P60 to P67
P70 to P77
P80 to P83
P4OUTCUT
P6OUTCUT
Supply VCC level voltage to pin Vcc.
Supply VSS level voltage to pin Vss.
Connect this pin to VSS.
Connect this pin to VSS via a resistor (about 10 k
 to 100 k).
The reset input pin (Note 1).
Connect a ceramic resonator or quartz-crystal oscillator between
XIN and XOUT pins. When using an external clock, the clcok source
must be input to XIN pin and XOUT pin must be left open.
The VCONT pin. (Not used in this mode.)
Connect this pin to VCC.
Connect this pin to VSS.
The VREF pin. (Not used in this mode.)
Input port pins. (Not used in this mode.)
The input pin for a serial clock.
The I/O pin for serial data. This pin must be connected with VCC via
a resistor (about 1 k
).
The BUSY signal output pin.
Input port pins. (Not used in this mode.)
The P4OUTCUT pin. (Not used in this mode.)
Recommended to be connected with VCC via a resistor.
The P6OUTCUT pin. (Not used in this mode.)
Recommended to be connected with VCC via a resistor.
Table 19.3.1 Pin description in flash memory serial I/O mode
Input
Output
—
Input
I/O
Output
Input
Pin
Name
Input/Output
Functions
Power supply input
MD0
MD1
Reset input
Clock input
Clock output
Filter circuit connection
Analog supply input
Reference voltage input
Input port P1
Input port P2
SCLK input
SDA I/O
BUSY output
Input port P4
Input port P5
Input port P6
Input port P7
Input port P8
P4OUTCUT input
P6OUTCUT input
Notes 1: When there is a possibility that the user reset signal becomes “L” level in the flash memory serial I/O
mode, be sure to cut off the current flow between the user reset signal and pin RESET by using a
jumper switch, etc. (Refer to section “19.3.2 Examples of handling control pins in flash memory
serial I/O mode.”)
2: For pins not used in the flash memory serial I/O mode, properly connect to somewhere in the user
system. For pins not used in the user system, handle them with reference to section “5.3 Examples of
handling unused pins.” For pins used in the flash memory serial I/O mode, handle them with reference
to section “19.3.2 Examples of handling control pins in flash memory serial I/O mode.”
Input